They put in place a system, decide player rotations and substitutions game-to-game, and try to stick to that system within the limits of squad depth, rest, success in varying competitions, and various other season-long strategic considerations. I think the analogy to baseball managers is pretty strong - just that baseball game results are less
reliable indicators of a team's superiority to another than they are in football (either form) or basketball. The better team probably wins/draws 90%+ of the time in the footballs, whereas it's more like 60-65% in baseball. Other than that, their impact on a given game, and on planning for approaching the season, seems largely analogous.
But if you don't like baseball analogies, take basketball. I can find as many examples as you like. The 2009-2010 San Antonio Spurs were 9-9, and later 25-18, despite an in-his-prime Duncan, Parker, Ginobili, etc. It was the same core team that had won it all 3 years prior, but the last year they'd gone out - shocker - in the
first round! Clearly, Popovich had lost his magic and it was time for a restart. Except, they don't have as itchy a trigger finger in the NBA, particularly when you're dealing with the most successful (
only successful) manager in the team's history.
The Seattle Seahawks could have cashiered Pete Carroll after two 7-9 seasons to start his tenure, or even when they drafted Wilson, went 11-5 in 2012, and then lost a crusher to the Falcons in the
Divisional. His defense wasn't clicking, they gave up 30! They were underperforming their talent level! Time for someone else to lead this squad to the promised land, right? Well, uh, no.
And don't get me started on Andy Reid. Did the Iggles fire him after successive losses in the NFCCG? Or when he failed to make the playoffs at 6-10 in 2005 or 8-8 in 2007? No, and then they ran to the NFCCG again in 2008 with, frankly, a rag-tag squad.
I don't know Hockey but I bet there are plenty of hockey examples. Look, nobody's arguing that bigtime euro football teams
don't have an itchy trigger finger. They clearly do, nearly all of them sans Arsenal. I'm just saying that they
shouldn't, and that it's self-defeating to be so impatient, and we have plenty of examples in other sports of great coaches being given the rope to figure it out and then ultimately doing so.