No way man. Those 6 of those 8 les were on stacked Bill Russell led Boston teams. Havlicek was at best the 2nd best players on those teams, and most often third or fourth best.
The last two were with Dave Cowens, who was clearly the best player on those teams.
Sure he won a Finals MVP, but he won it in possibly the worst era in basketball (ABA, cocaine), and besides, Tony Parker, Billups and Dennis Johnson (God bless his soul) won the Finals MVP, but they are no where even close to top 20.
Finally, for a guy who plays in a weak position (SF and SG in the 70s is pretty weak) for 17 years and only made all-nba 1st team four times actually tells you something. He was, at his peak, the 5th best player in the league, and that when all the high flyers went to the ABA to cash in.
Hondo is a great hustle guy, extremely inefficient, but played for a long long time. He had a motor that wouldn't stop, but he is like Jerry Sloan on steroids, or a less efficient Frazier (who I'd pick over Hondo). No way was he top 20.
Top 10 (in no particular order):
Wilt
Russell
Jabbar
Magic
Jordan
Bird
Duncan
Moses
Hakeem
Shaq
Next 10 (in order):
Big O
Lebron
Kobe
Garnett
Dr J
Walton (peak was way too short, he could have been top 5)
Robinson
Kobe
Isiah
West
Hayes was the ultimate ball hog. The league had a few guys like that (Walt Bellemy for one), where he put up empty stats on crappy teams. The Bullets team was widely considered as one of the weakest championships of all time (along with the Sonics), and Dandridge and Unseld were better players than Hayes.
Hayes shot 45% as a big man in the 70s for his career, I mean, how do you even do that? He's like a super charged Shareef Abdul-Rahim. I am not trying to bash him, but there are many players I'd pick over Hayes. Many.