This narrative of yours makes no sense. Yzerman literally completely overhauled the team's strength and conditioning department when he came in as GM because it was so out of date from the Holland era.
Great conditioning is not gonna turn a roster into a squad of fighting goons.
Also, every team deals with countless injuries every season. It's not exclusive to Detroit.
Look at the chart since 2009 (with a bunch of Holland-era seasons included) vs. the chart from last season up until March 10th. Detroit is middle of the pack. There are no strength and conditioning issues.