Also we have:
'18 Cleveland finished 4th in the East. Helps to have LeBron, though had little chance against GS in the Finals.
'10 Celtics also finished 4th. And they had a real chance in the Finals.
Both of those teams finished 50-32, which the Sixers are on a pace for as well. Cleveland didn't have a beast like Milwaukee standing in their way, but you can argue the '10 C's did (with MVP LeBron and peak Dwight Howard, playing on the 2 best teams in the league).