Quote Originally Posted by missik
is there a mod where they only change the AI formation for you?
i dont want to get a whole new mod because I've made a lot of changes to my RTW vanilla so far
Yes there is. There are two as it happens; Darth Formations & Sinuhet Formations, you can install them as is without having to do anything else.

Here's the Darth Formations 16.2 Super Pack link. Several Files come with this download, the one you want to install for use with Vanilla RTW is the "Generic Standalone Version".
http://www.twcenter.net/forums/showthread.php?t=62465

The second formations mod you can use with vanilla RTW is Sinuhet's Battle Formations. Here's the link where you can find this formations mod.
http://www.twcenter.net/forums/showthread.php?t=58952
Both are a big improvement over the vanilla stock Battle AI and can be installed as is with vanilla. Follow the instructions with whichever you choose to go with and you will be good to go.