According to whose tier list? I would put montana and oscar mike at upper A tier as well, I don’t think it means they should get nerfed though. He only has the highest damage output in his ult, where he looses out on alot of his survivability. (due to not being able to put up rotating wards and block with aegis.)
@V0LUM3 Oscar Mike is miles better than the others in a similar role as him, not because he is too good, but because the others like whisky foxtrot aren’t so great. It’s possible the same is true for ISIC. Boldur for example seems like he could be doing better. Atticus as well. I think he was on par with montana prior to the nerf, their kits have alot of similarities.
If he really needed changes, I think smaller changes should be used, like @tmcbron said, reducing aegis damage blocked by 20%.