Well Jacob let me stop you right there because we don't need to talk about if this would necessarily benefit Adult Swim or even any anime companies. Adult Swim asked people if they wanted it back. Which means regardless of anything else they're willing to give it a shot.
I highly suggest making a stream on top of a broadcast but there is still value to broadcast. Here's the thing about the value of the broadcast though. People still do watch television as it airs believe it or not and we're talking about rather dedicated people. ASA already does reasonably for it's time slot. A little more life injected into that and some better promotion and they might have something there. Furthermore while this doesn't mean they couldn't just do a stream, free dubs are harder to get than free subs for the majority of shows. Which is why this has value beyond the sub-only streams and the 2 to 4 episode previews Hulu from FUNimation.
Yeah it's late and that's why I think 9PM is a better start time for Toonami on AS and comedy can have the early morning hours to catch the people coming home from parties and bars and such. Only Family Guy does particularly well in the first 2 hours and when they experiment with other comedy than The Boondocks or American Dad in the 11 hour it usually goes south. So I don't think it's entirely out of the question they could get those better time slots 9PM - 12AM and end earlier if the right deals are in place to make up for not using Family Guy at 10:30 PM. But I also think simply running their existing anime block in those hours and comedy in the early mornings on Saturday would actually improve the average for that night because where Saturday is really struggling is 9PM as it's very skippable and after 2AM when viewers are not interested in watching philosophical debates but would rather get some cheap laughs. 12AM-2AM generally does very well and arguably comedy would not do better in those hours due to people not being home to watch it. They use the dedication of anime fans to make those hours work right now. I think they could do the same with 9PM-10:30PM (everything before Family Guy) and also get 10:30-12AM even with their current line-up. They just have to believe more people will watch and right now they are determining if that is the case.
However, 12AM-2AM isn't exactly useless either. Premieres have done well there in recent years and any amount of TV exposure is good for the anime airing on ASA. It seems like FUNimation wants to stake their claim of those hours again because ultimately streaming doesn't pay the bills and TV airings even late at night can still do more than just streaming can.
See --- in my ideal world, Cartoon Network and Adult Swim would play nice. Basically, I'd like see the lines blurred a bit where Toonami is concerned. A rigid "Toonami must end now because Adult Swim is beginning / ending" feels very counter productive to scheduling.
Now something that has to be acknowledge (and pointed out for those who don't know) --- [AS] and CN are two different legal entities and its understandable that, for spending and income purposes it might not be WHOLLY feasible, but ultimately I think it really is logistically plausible to simply say "Ok, from 7-9 is on Cartoon Network, they foot the bill and get the profits, from 9-12 is Adult Swim, they foot the bill and get the profits". Another possibility entirely (and maybe safer for the future) might be to separate Toonami into its own legal entity and give time from Cartoon Network, Adult Swim (and maybe Boomerang) to Toonami. That would really give them more maneuverability and magically some of these concerns about demographics goes away because Toonami will target who they feel they need to target. That being said, it would be nice if Adult Swim and Cartoon Network play nice with their properties.
Something to point in the broad spectrum of things --- for me the main time play comes in from acknowledging that CST and MST does exist. 3PM EST is a horrible time almost exclusively because that translates into 2PM CST. There are *A LOT* of cartoon viewers in the CST time zone. MST certainly carries viewership too, but generally, not in the number scopes CST does based on demographics. This isn't wholly relevant to your arguments, but I felt this was a good thing to point out non-the-less.
That being said --- I think as a general rule we can agree from 3-5P has viewership problems for a slue of logistical reasons. Kids are getting home from school activities, etc. Idealistically, in my mind, I don't want to elicit a SOLID reason to make kids want to rush home. School activities are something they should enjoy.
3-5 is a stigma left over from Fox Kids and Kids WB when that was the time the networks gave them before they moved onto more adult orientated program. We don't necessarily need to dwell on that. This is a network for animation after all!
That being said, to me the more important aspect is when to start and what viewers you want to target when you do.
Toonami ending at 9PM isn't exactly counter productive unless action on Adult Swim started at 9 you see.
I'm not seeing how CN and AS do not "play nice" Brak and Zorak are back on CN and Toonami showed up on Adult Swim. That's plenty of evidence that they are willing to share but they will do so only when it seems like ratings or interest can be garnered. Star Wars the Clone Wars also has been shared due to it's adult draw. Potentially other shows could be but at the end of the day CN has plenty of time for their shows and AS has plenty of time for theirs. The only possible casualties there are the shows that blur the lines but they are handled on a case by case basis. I don't think the various cancelled shows of CN's recent past would have survived any better on Adult Swim. Not even Sym-Bionic Titan. ThunderCats maybe but mostly because of all the nostalgic value it has.
Honestly I don't trust CN with Toonami. Not until the current guys leave, I'm not looking to get them fired I just don't want them bringing back Toonami only to cancel it again and make it look worse to potential feature CN executives. I'm all for them establishing an action block that would lead into Toonami on ASA though.DC Nation deserves prime time and so do ThunderCats and The Clone Wars. Be that on Saturday or some other night that isn't Friday.
In a more ideal world Toonami would be an all ages block that could mix top American action cartoons with uncensored or lightly censored cartoons from other parts of the globe. But demographics are in place for advertising reasons and the Toonami name has much more value with adults now than kids. It could have value to kids again but I don't see CN's current guys making use the brand much less doing so well if perhaps no other reason. I certainly would not mind CN and AS sharing Toonami but if AS were to start their Toonami at 9PM... unless it cut off at 11PM I don't think it makes much sense to have a Toonami block that runs through CN time into AS time and the demographic issues it would ensue would be numerous. No I think if CN wanted to target Toonami at older audiences but on their time then they could simply take back the 9 hour and even the 10 hour on Saturday. Why complicate things with a split but if they did that it's a bit unlikely they'd allow TV-14 shows on it and that's the main value of airing Toonami on Adult Swim, less or no censorship.
You can't make a few hours a week of programming a separate entity. Adult Swim didn't get that until it was airing 6 days a week for 6 for 6 or 7 hours. They could make half of Boomerang Toonami sure but unless they got a bunch of new action shows that would get stagenate as all get out in a hurry to have Toonami for 6 hours a day. A block on Boomerang is plenty feasible for rerunning CN's action programming over the years and whatever Warner action series they have on hand still but that would require a lot more bumpers than one night of programming and without the potential benefit of having something to help pay for it.
3-5 is not a good time for the reasons you mentioned and that's why CN would give that to action. If they assume their best hope for ratings is with total viewers then they'll play action mid-day. As far as trying to get kids to watch action they do so entirely in the morning hours because they want to keep reruns of their top comedies in those easier to catch evening after school hours before prime time. They tend to run nothing of importance 2PM-4PM as it is. It's far from ideal but it might be the best you can hope for from CN. When you think about it, weekday mornings isn't an awful time to target action cartoons to young boys but I do wish action could get more visible slots at least one day a week and if Saturday morning is the best we can hope for that's rather disappointing.
Getting back to Toonami on Adult Swim. There is a great deal of potential there and for once they wont have to worry about skewing too old. I never thought they'd even consider it as ASA was always attempting to be "your big brother's Toonami" but often failed miserably at that due to lack of atmosphere in recent years as well as airing shows like Kekkaishi that probably would have been cancelled within weeks on Saturday Toonami like several other shounen anime.
As the Toonami audience is now the Adult Swim audience it makes a lot of sense to try it. ASA while not doing bad is still likely on the chopping block and Toonami might very well be able to save it even if they went about this with minimal effort. Because anime is much more popular with 18+ now in America than kids it seems to me like pushing new anime with the Toonami brand is much better suited for Adult Swim at this point and CN's own action programming can do without Toonami just fine.