Isiah Thomas and Bird are in the same level. They both won 2 or 3 championships, were clutch and had amazing stat filled careers.
Unless your a homer you can't say Bird is so much better than Thomas. And don't even put any basketball player in the same level as Jordan. The guy is the best player ever to have played the game. If he didn't semi retire the bulls would have won 7 to 8 championships
I'd have to guess you didn't see the players you're discussing play.
Thomas: averaged 19/4/9. 12 time all star, 3 time all nba 1st team, 2 time all nba 2nd team, 1 time finals mvp. No league mvp, finished top 5 in the voting once (5th).
Bird: averaged 24/10/6. Also 12 time all-star. Rookie of the year. 9 time all nba 1st team, 1 time all nba 2nd team. 3 time all defense 2nd team. 2 times finals mvp. 3 time league mvp, finished top 5 in mvp voting 9 times (3 1st, 4 2nd, a 3rd and a 4th).
In every healthy year of his career, Bird finished higher in mvp voting that Isiah ever did. People debated whether Bird was the best ever when he played, while Thomas was always considered a top 2 or three point guard in his time.
Jordan's definitely in the running for best ever, but most of his competition is from Bird's era and earlier, so you'd probably put them on Thomas' level.