1. Sabo
2. Burgess
3. Luffy/Hakuba
4. Chinjao
5. Diamante
6. Cavendish/Bartolomeo
7. Sai/Ideo
8. Bellamy
I believe Burgess is stronger than Luffy because story-wise it should be the case. We're talking about the first division commander of a yonkou here. Besides, Oda avoided a confrontation between them during this tournament when he had more than enough motives to compare them. Instead, Luffy was forced to leave the tournament and Sabo to take his place. I believe he did it because Luffy wouldn't have win the fruit if he was still in the tournament, so he choosed someone stronger(Sabo)
As for Hakuba he got a similar hype to Burgess when he wiped out his entire block in an instant, having a speed someone on Bartolomeo's level(who fodderized a vice-admiral) couldn't see and impressing even the number2 of the revolutionary army. Besides, it's only a temporarily mode, so it should be that strong. Luffy isn't to be underestimated either. It's for that reason i think it can go either way.
At first i ranked Diamante to be on a similar level to Burgess, but he disappointed me. Besides, story-wise he should be taken out by Kyros(someone with whom he has a story with) and i don't rate Kyros that particularly high, so i put him below Chinjao who at least was capable to push Luffy to mid difficulty