Yes and no. It seems the AI can't decide what to do with it's reinforcements: at one time thinking they should act under the banner of leader X, only to conclude that perhaps it's better to wait until X is dead and go with Y instead. Upon which it reflects and decides exactly otherwise again.

The problem is alleviated when/if you destroy/rout the other army; then they will get some sense and cohesion again. But whether or not this is actually a problem caused by EB code (in txt files) or by some weird and unforeseen interaction between various routines in the RTW.exe (beyond our powers to heal)...