They are not trimmed too much, in fact, they are not trimmed nearly enough. As Joseph remarked above, the "screen accurate" helmets were all over the map. But, with regard to the ear gap but the the ear disk is usually trimmed tighter... an 1/8" or just a little more. That change would make your ears fit much better. Try trimming just a tiny bit and see what you think.
It takes a while to get it perfect. I put a lot of hours into mine before I was happy, about 30 on the helmet and the ears took three or four sessions at about 4 hours each. They got trimmed, bolted and re-bolted at least twenty times and even punched a few more holes to make them fit better. Paul (Troopermaster) gave me the tip he uses which is to trim the disk to a consistent height of about an 1/8" or so against a flat surface and then work the rest of it to make it fit. Mine got completely reshaped from my original cuts before I ended up with something I was happy about. I still feel they're too thick on the lower part and I'll probably go back in one day and reshape them again now that's I've done it a few times and am less nervous about it.