I also have a problem with fleets in tactical. My (retrofitted transport)light cruiser missile ships come too close to beam ships then as they retreat after firing the followers stay in beam range instead of just backing up. So I cleared all group assignments and manually moved every ship every turn, which is a pain but results in no damaged ships till you hit the wall.

Also orders resolve combat does not work well on missile ships mopping up ships which have no weapons and are retreating. The problem is they fire at extreme range and as the enemy moves he gets out of missile range. Once again the solution is manually moving though I suppose changing from optimal to point blank would help. I did not want to take the chance of getting rammed by cruisers though...