It is compatible with RC/RR Jan 18 for TATW 1.4.
The Battle AI files are similar but the included BAI are based on XBAI 3.4 which is done by the XAI team, which improves upon the one done by Darth.
With regards to the unit cohesion, there may be different factors that's affecting it, one that springs to mind is unit size (mainly if you are playing with Large unit settings). I am playing on normal unit size, and the only unit cohesion probs I have seen are with the Orc/(evil) factions where they tend to bunch up.
Could you clarify further what problems you are having?
With the unit charges are you talking about the cavalry only? Or all the units? The cavalry fix can be found with Mephisto-X
sub-mod for RC/RR.
Try the BAI files included to see any difference, making sure that you run the FILE_TASK.bat before trying the new battle AI. The units should charge more as one and not only a few at a time like I noticed with vanilla.