Detroit's top 5 players (including Melo) would be a problem in a playoff series for any Eastern Conference team.
Rose, Carmelo, Griffin, Drummond, Jackson
As currently constituted. My top 5 teams in the East are:
1.Toronto
2.Milwaukee
3.Boston
4.Philadelphia
5.Detroit
I see Detroit winning 45-48 games and being the 5th seed. If they add Melo, 48-52 games would be doable.
Trust me, none of the top seeds would want to face 3 proven playoff performers in the playoffs like Rose, Carmelo, and Griffin in a playoff series.

