Hello to everyone

I wanted to add an aquilifer to the legionary first cohort, but after doing the entire process and starting the game (I have added succesfully several new units to other mods that I play), I noticed that nothing changed despite the fact that I did everything right. Also some time ago, I had attepted to add the testudo formation to Polybian Principes and Hastati and despite the fact that I added the formation, nothing changed again. I would like to ask whether is it possible or not to tweak some aspects of EB according to our taste and how? Any help would be great!

Regards