I've been tracking Hockey East coaching records for several years now. First, including this season Coach Leaman is 191-112-44 (0.614) at PC. Second, you gave Coach York's overall record, not his record at BC; including this season he is 622-323-87 (0.645) and over the past 9 seasons (the same as Coach Leaman) he is 209-111-28 (0.641). So Coach York is flat out better than Coach Leaman.
Coach Bazin is currently 203-110-31 (0.635), also better than Coach Leaman and just slightly behind Coach York. But besides overall records, what about league records, post-season records and titles? Here are all three coaches records for overall, league, regular season, out of conference, Hockey East Tournament, NCAA Tournament and combined HEA & NCAA Tournaments:
<img src="https://www.buhockeyarchives.com/Charts/York-Bazin-Leaman.png">
As can be seen, over the past nine seasons Coach York leads in five categories, trailing Coach Bazin in Hockey East Tournament play and last in OOC play. Coach Leaman is last in 5 categories and 2nd in 2 others. If you want to go beyond just wins and losses and include post season play and titles then Coach York is still the leader, but has dropped off the past several seasons. Coach York has 5 HE regular season titles ('12, '14, '16, '17, '18), one HE Tournament title ('12), five NCAA appearances ('12, '13, '14, '15, '16), three FF appearances ('12, '14, '16) and one NCAA title ('12). Coach Bazin has 2 HE regular season titles ('13, '17), three HE Tournament titles ('13, '14, '17), five NCAA appearances ('12, '13, '14, '16, '17) and one FF appearance ('13). Coach Leaman has one HE regular season title ('16), six NCAA apearances ('14, '15, '16, '17, '18, '19), two FF appearances ('15, '19) and one NCAA title ('15).
Sean