Locally I think the penalty should only apply if you are erect, so it could be prevented with a cage or something like that, possibly built into the character's armour. That's what I was going to go with, but maybe that is too much details.
Seems like despite his large size, Carric will be more of an adaptable melee combatant, not the part's powerhouse. With blink shirt (which I was thinking of refluffing as a sort of "rebirth" as his body collapses and dessicated, hatching out of a spoor which are deposited on most surfaces within the immediate area) and a sizable grapple modifier he can identify threats and gank them, or at least attempts. Mental stat wise he is quite wise and reasonable intelligent but lacks self confident as he feels himself inferior to his Queen, as a loyal subject should.