Yeah Bednar's systems require full effort all the time and over 82 games, it wears a team out. Especially when one line is laying 21-22 minutes a game. It also causes a lot of the penalty issues that the Avs have. Bednar's teams have always been near the top of any league with regards to number of penalties and a lot of that stems from tired legs.
That's actually not true. His teams have been pretty middle of the pack in PIMS for all but one year.
I think his system is contributing to some of the bonehead penalties the Avs are taking for the reasons you mentioned, but the common theme between his teams in the AHL, and now isn't PIMS, it's that they're not very high scoring teams.
I think that lack of scoring also has to do with his system, as I think only elite athletes like the top line can skate as hard as he has them do at 100% effort for 82 games, and still have the poise to settle pucks and finish scoring chances regularly.
2007-08 Stingrays - 21st in PIMS - 4th in goals
2008-09 Stingrays - 15th in PIMS - 4th in goals
2010-11 Rivermen - 3rd in PIMS - 18th in goals
2011-12 Rivermen - 21st in PIMS - 12th in goals
2014-15 Falcons - 12th in PIMS - 26th in goals
2015-16 Monsters - 10th in PIMS - 17th in goals
Another important thing to note is he’s never been a head coach for more than two years until now with the Avs. I don't think he likes to adjust his system, and he hasn't had to much in his career with the short stints as HC.
Standings
TheAHL.com