Yeah, I won't have to see the same 4 characters all over the place seems to me one good thing would be diversity just off the top of my head. I certainly can't think of anything bad like it seems you're hinting towards by saying NOTHING GOOD will come with this feature. Not like it can get worse if you add a variety.
As for pegs idea I can see it being abused with personal avatars and it would put a toll on Admin to make sure there arent explicit or vulgar pics on EVERY single character's pic hard enough keepin an eye on the clans' pictures.