I would tell any UFC fighter to not take this fight. Not because I see Cormier as a challenge or legit threat, I don't. It is because he isn't in the UFC, plain and simple. Ronda and Cormier are on the same level. Sure WE know who they are, but your average UFC fan has no clue. Why go and fight someone where it is literally lose/lose? You beat him? Great, you beat non-UFC level talent*. You lose? You must really suck as you lost to non-UFC level talent*.
It makes no sense for the UFC to keep trying to pull from within it's ranks, go ahead and grab Arlovski, or Fat Timmy and get Cormiers contract over with so he can be brought into the UFC and we will find out if he is legit or not.
*While he may or may not be UFC level, the casual fan will thinks that all the UFC level talent is in the UFC. Any fights that take place anywhere else don't matter.