If you can use the ships themselves, with the threat of collision as a weapon, then it changes the gameplay significantly. It favors the Empire significantly, as they have more ships and are more maneuverable.

Also, with the ordered movement, you would somehow need to keep track of which ships had been collided with earlier in the movement. As it is now, it only concerns the active ship.

The simple fact is that it encourages more and better tactical maneuvering if overlap only (and negatively) affects the actively moving ship.

I'm good with the rules. The one who does the hitting gets the worst of it.

I think you guys need to stop thinking about it as a collision.  The word collision is no where in the rulebook.  This is just the rules for overlapping bases.  Nothing more.  This game hasn't even been on the street for a month yet and you're trying to change the rules.  Please, try playing the game for a while with the rules that came in the box.  The more you play, the better you get at choosing maneuvers, and the occasional base overlap won't be that big of a deal to you anymore.

Roy