I couldn't find anything quite related to this on this forum; therefore, I have taken it upon myself to post a solution to Germanicu5's stubborn hardcore battle AI, which refuses to allow the player to control their units in some situations. To fix this problem, open up your campaign script within the KGCM mod's folder--C:\Program Files (x86)\SEGA\Medieval II Total War\mods\kingdoms_grand_campaign_mod\data\world\maps\campaign\imperial_campaign for myself-- and push ctrl-F.
Search for "Germanicu5 ReallyBadAI Hardcore," then highlight everything following those words until you reach "ADDITIONAL SCRIPTS." Delete the highlighted portion. After this step, there should be nothing following "Germanicu5 ReallyBadAI Hardcore," and you can even delete that line if you wish.
I hope this helps you guys because it has frustrated in no small manner to not be able to control my own units.