What I did was actually... much less involving than that!
Rather than rotate them the way you're trying to, in my game I just made them snap instantly to the new angle. It wasn't pretty, but with such a short deadline, "pretty" wasn't my focus.
Anyway! I found a pretty simple solution for you. Rather than use individual pointers to guide the enemy along the turn, we can use the "rotate __ degrees" actions to take care of all that for us. It took a wee bit of tweaking to get the pointers at the proper places, but it seems to be working just fine!