The notion that “there can only be one” is as bogus as the Highlander sequels (I can’t even remember who dragged me to see Highlander: Endgame, which is probably for the best). Whenever I see people fighting off the existence of another Super Smash Bros. or Mario Kart challenger from another publisher I’m utterly confused: competition is good.
There can be more than one Monster Hunter too, as Dauntless demonstrates.
Source: Destructoid Dauntless is a fine action romp, but its biggest accomplishment is true cross-platform play