I think CP3 on the current Pistons is a 50+ win team, especially if Detroit doesn't have to give up Kennard to get CP3.
The Celtics aren't going to be dominant and the 76ers are one wrong Embiid step from being a 47 win team and a second round exit. The Bucks are going to be really freaking good, but Bledsoe is a mega choker and Middleton did not exactly bathe himself in glory against the Raptors either. The Pistons would have a chance against the Bucks in a 7 game series.
If you are the Pistons, why not go for it? Paul is $50 million cheaper than Westbrook, and he would be a good fit on that team. Griffin's game has matured a lot in the last few years, and Drummond, Griffin, Rose, CP3 and Kennard is a solid starting lineup. Detroit is never going to attract marquee free agents, so why bother saving the cap space?
Edit: The Pistons also have leverage, because the minute Bradley Beal goes on the market, CP3's value drops.