Thread:Tausendberg/@comment-1037137-20160615230257/@comment-26932251-20160616002844

I'm lead to understand that Eren appearing in his titan form was supposed to be what stopped them from sticking to the plan of completely breaching Wall Rose.

Also, there were a lot fewer titans and a lot more soldiers and more and better cannons than at Shiganshina so if Reiner appeared prematurely then maybe he would risk getting fired on by cannons that could actually break his armor (such as what thunder spears are apparently able to do).

That's the best explanation I can give. There's a lot that doesn't add up with the information that we have, like why did Grisha happen to kill Frieda right about the same time as after Shiganshina was breached for the first time in 100 years.