One more thing worries me, thou. Is there any way to have two... lets say "Type 1"- minion instances to collide and cause different results to each other? I kinda am under the impression that bad code will cause an instance to do nothing at all by collision or just use it's own damage against itself and other bugs like that. Maybe an example of what I'm rambling on here about is:
Condition: Type1 collides with Type1
---> Subtract Damage(Type1) from Health(Type1)
I can leave such a difficult thing out, but that would mean no individual upgrading, individual damage and such? If there's a mass of Type1 minions and they can't in any way tell each other apart, I can really make them only bounce in collision, don't I? I fear that a really elaborate code or loop or similar would cause too heavy requirements, at least if I make them wrong. (I have barely just began to test all the tips I had from all replies so far so sorry if any one of those actually deals with this matter too.)
I know one way would simply be to make upgraded units new objects but that would only push the problem to that mass of instances, wouldn't it? Those instances would again be clones when comparing their abilities?
And I presume that since bullets could pick up object's damage value to deliver onward, the problem is not shooting units but melee units, right?
EDIT: Of course it can be overlapping in stead of collision and so on, but too heavy way to make instances use individual information like altval based damage and such against another instance of the same object would just be too much trouble for it's worth, wouldn't it?
EDIT: Any link to a post that deals with this issue is okay too. Or telling me that it's impossible, he he.