I don't even really see what the problem is.
For most helmets they could just have the ears stick out, it'd probably look fine even if they were just clipping through like there were holes in the helmets for the ears.
A bit silly yes, but cmon this game doesn't have '' realistic '' armor or gear that '' makes sense '' to begin with.
Or they could just simply have the ears go away as if they've been folded into the helmet or something I dunno.