Love this observation from Marchy. In debates about which player from an era was better than another player from a different era people get too caught up in stats, player conditioning, equipment, advances in medical treatment etc. What Marchy is talking about needs to be heavily factored into any comparisons when it comes to players from a bygone era.
While true there is no denying that the NHL of the O6 era never had dmen such as Burns, Paryako and Pronger on the back end keeping it to just Canadians.
I looked at the rosters of O6 teams in 1966-67 and there were only 2 D men listed at 6:03 (Doug Jarrett\Bert Marshall) and it looks like 3 more at 6:02 who played more
than 35 games (Jacques Lappierre, Ted Harris, Jim Nielsen). Granted they went 5 D back then but its basically 1 D man per team 6:02 with 2 teams with 1 at 6:03.
Then add in the size of the goalies with Montreal's at 5:07/5:08 and Detroit's Crozier at 5:09 and Chicago's Hall at 5:11.
Compare to just Canadian Dmen of today and you have Hamilton, Parayko, Power, Burns, Ekblad, Nurse, Sanheim all taller than any O6 Dman. Than add in Pietrangelo, Peleck at 6:03 and Chabot, Chychrun, Theodore, and Severson at 6:02 and as a group in totality its no contest.
Absolutely the cream of the crop such as Orr, Lapierre, Horton, Howell, Tremblay, Stapleton, Mohns, Bergman, Baun and Nielsen are right there from the O6 but
you can't teach that height and todays guys are too numerous.
So Marchand assuming the O6 guys have todays technology and training would in all honesty have a field day shooting on those goaltenders and would do just fine matching up against shorter dmen.