You can't win paying a "superstar"
I think this is just an indictment of how all "superstar" level players are overpaid. It's like buying anything else: you get the best value in the middle of the price-performance curve. "Superstar" players have ~$25M/yr contracts, which is $5M a win. The free agent market is chock full of 2-3 WAR players for $3-6M. It's just another way of saying there's only so much one guy can do, even if they're a true superstar (and not an arguably struggling one like Mauer). It's never worth it. And while the Yankees of the world might be able to sign such contracts anyways, the Twins can't afford it if they ever expect to win.
anything from 5.0-6.0 [WAR] is "superstar" level