[romey]

Two things: First, I don't think that huge kinetic weapons would be the ideal choice for this kind of combat. If I'm attacking an asteroid with a huge ass gun on it, I'd first like to have some type of EMP type weapon developed to simply shut down the tracking/aiming/power supply of the asteroid's defenses. Just the threat of an attack like that from orbit would probably be enough, as it would likely shut down life support on the rock as well.

Secondly, assuming that such a weapon isn't developed, depending on what you're mining, it seems likely enough that it won't matter what shape the asteroid is in. For mining solid materials, it would probably be best just to blow these asteroids into manageable pieces and send the whole lot through your enormous space processing plants for extraction and refinement. In this case, you'd need space fleets to protect your "planet crackers" and to protect your processing vessels from other companies, pirates, etc.