Not sure if this has been suggested before. But what about splitting off the offensive powers in the mastermind primary sets into a third set? So instead of a thug mastermind having to use a pistol they could use other offensive attacks like dark blast, mental blast etc. For example you could have a cult leader who has thugs/cult members and uses dark/blast (dark magic) or a powerful psychic who has thralls and uses mental blast powers. I guess an easier but less elegant way to accomplish something similar would be to add more primaries like thugs with dark, thugs with mental, etc.