Nah, not even close to overthinking it. This is just thinking it through.
He can get hurt whether he plays every game, or 3 out of every 4.
Fatigue due to overuse is a massive contributor to injury though. Sure, he can get run into by someone in any game but for things like pulls, strains, and tears, workload is a massive contributor to those. If we can reduce his workload, we can reduce the chances of that happening.
There's a reason he's gone his entire career being a good goalie that doesn't play a lot. Acknowledging that and load managing him isn't overthinking. Fuck, we watched our basketball team load manage their way to a title not that long ago, this is basic sports science, not particle physics.
The Panthers needed 24 games over ~65 days last year to win their cup. The most Stolarz has ever played in a similar time frame before this season was 13 games in 54 days, that ended with him missing a month with a knee injury (no surgery, but he missed a month)
His heaviest workload of his career over a similar stretch was this season where we played him 17 games in 64 days. That stretch of course ended when we had to shut him down to have another knee surgery.
This isn't overthinking it in the least. This is just being mildly aware of the physical limitations of the player we're talking about.
Even a 24 game in 65 day workload is kind of underselling it because the finals is a much lighter workload than the first 3 rounds. There's about a week off before the finals and then 2 days off between most of the games. Florida played 17 games in 32 days to get to the finals. Stolarz simply can't handle that workload or anything particularly close to it.