Excuse me but how would a Mario Warriors game be boring? Seeing as Mario has a lot of powers ups they could give to characters and they can pull characters from over the franchise. Plus just imagine having Bowser be like, what who are all these idiots who keep trying take my spotlight?! Plus mixing in Paper Mario and Mario and Luigi series with main canon lines, would be really fun.
It's moreso the fact that people other franchises to get at the Musou money train, not Mario because we have to. I mean we can't just put Mario in everything now, can we.
Plus Shiggy said they were looking at other franchise crossovers like HW, SMTXFE and Super Mario Puzzles and Dragons.
Like Kirby RPG, Metroid arena based shooter (inb4 Splatoon comments), Captain Falcon 2D Beat Em Up and other genres.
Hell let's take a Nintendo franchise and put it in a genre that it would never fit, add good gameplay, heavy amount of fanservice and great music and we got a Mother Platformer from Wayforward