Umaga, Khali, the Highlanders, the list goes on.
Um... Did you know that both of the Highlanders are Canadian ? So it is not a stereotype since they are Scottish, the WWE just wanted a gimmick going in that direction, I mean you're not gonna have Canadian guys playing a Scottish person who is plain and simple and contemporary.
Umaga ... Well... I guess you should say Jamal... Samoa Joe rip off ? I say NO ! Umaga is pretty bad in the ring for sure, and can't do mic work, but he has a good manager and everyone knows Vince always likes big ones

.
Khali... Not going to say a word on him. He's fine as a manager ONLY to intimidate I guess, but ECW wtf ???
So to come back to stereotypes in the WWE. I think that they do not overuse them at all, I mean they just use a few out of so many wrestlers, it's inevitable. Cryme Tyme, Shelton Benjamin : stereotypes. Bobby Lashley, KING Booker (not the old Booker), Farooq at the time : don't tell me they have been using stereotypes for their characters, these are World Champions with talent who were recognized for it, without having an "offensive" character.
Add in a few stereotypes and the money comes in, I mean come on it becomes REALLY entertaining. Isn't that why someone would still watch WWE ? I mean let's face it 1/5 of the matches now are actually interessing to watch only, the entertainment is in the storylines.
A few stereotypes in WWE does NOT mean racism, this is entertainment ! We could say the same about movies, but we don't, because a movie is fun to watch, and there are different characters, some of which include stereotypes. I think the WWE is not offensive on this subject. But there are other things that are (backstage mostly), but I'm not going to start to talk about those.