[neatoman]

I guess this might be a good time to bring this up, when did the first one even take place?

It can't have been before the end of season 3, the Turtles and Triceratons didn't know about each other before that point. It can't take place during the first half of season 4 because the Turtles were in space. It can't take place in the second half of season 4 because Shredder is in no way implied to be hospitalised or a monster.