Grant Williams: Tier 5A (Between 85 and 125)
Malcolm Brogdon: Tier 4B (Between 60-84)
Derrick White: Tier 4B (Between 60-84)
Robert Williams: Tier 4A (Between 41-59)
Marcus Smart: Tier 4A (Between 41-59)
Al Horford: Tier 4A (Between 41-59)
Jaylen Brown: Tier 3A (Between 20-24)
Jayson Tatum: Tier 2A (Between 9-10)
So, assuming there's an even distribution of talent in the NBA (there isn't), that means we have:
(1) #1 starter, top-third
(1) #1 starter, bottom-third
(3) #2 starters
(2) #3 starters
(1) #4 starter
So, eight starting caliber players, with five of them capable of being top dogs or sidekicks.