Honestly, I thought keeping Attack on Titan to start off the block wasn't a good idea. I could understand that Attack on Titan is popular, but giving reruns to start off the block is not really good in my opinion. It would have been better if Titan reruns aired later. I would've preferred that DBZ Kai should had started off than Titan reruns. Hopefully, DBZ Kai might help the ratings since it will start the block.
I didn't think that it was a bad idea to start off the block with Attack on Titan initially. I thought that it made sense given how well it did with that Labor Day marathon and they probably figured that it would still do well starting off the block in spite of being reruns. It made more sense to keep it at the front of the block than say the season one reruns of Space Dandy in my opinion. Over the last few weeks however, it seemed like starting off with DBZ Kai would be a better move, which is why I'm not too surprised that they moved it up.