[Q]

I agree that at the moment it is not very attractive to build larger mines (I never do!). The idea of counting the larger mines as three units for the minesweeping would be one possibility. Or if you would restrict the ability to sweep larger mines to sweeping components of higher tech levels? Or a combination of both: Large mines cannot be sweept by sweeping components level I and II, level III will sweep one large mine, level IV two and level V three. For small mines everything remains as it is and for medium mines it is in between.