The Bucks just need to add some "regular season" guys that can eat up some minutes and allow them to win enough games to be a top 3 or 4 seed. This year proved that sitting guys out for rest, winning the equivalent of 52 games over an 82 game season, and being a #3 seed is better than winning 60+, playing more regular-season minutes, and being a #1 seed. The Bucks won 2 of the 3 high-pressure road games they had this playoff run (they won Suns Game 6 and Nets Game 7, and lost Nets Game 5 when Durant went off). They don't need the home-court advantage and are better off optimizing health.
They need guys like Forbes who can be effective against crappy teams and soak up minutes but aren't necessarily going to be getting minutes in the playoffs.
When it comes down to it next year in the playoffs (assuming everyone is healthy), the rotation will shrink to 8 guys. 6 are already set (Giannis-Middleton-Holiday-Lopez-DDV-Connaughton). If they can somehow bring Tucker and Portis back, that's the whole rotation. Otherwise, they have to replace those two guys.