This isn't Celtics News, just highly unlikely hypothetical scenarios, but assuming that Tatum comes back and is the player he was before the injury, there are very few peers. The following list is the candidates:
1. Jokic (Still the best in the league in my view)
2. SGA (debatable to be ahead of Tatum, but most would likely have him at #2)
3. Tatum
4. Giannis (he has dropped off)
5. Doncic (still a top player but not as much of a lock as he once was)
6. Embiid? (Not sure he is still on the list due to injury)
Then you get into the next tier that in my view includes (in no particular order), Brown, Edwards, Mitchell, Brunson, Maxey, Wembanyama, and maybe some others. Then some old guys like Durant, LeBron, Leonard, Curry.