Managers obviously matter. If they hired me, the Twins' fortunes would plummet. Maybe plummet less if they hired you.
The difference among the 30 people who actually hold that title, though, may not be as much as you imagine. There's the source of the disconnect in my view.
It's why the notion of "Rocco supporters" seems like a strawman to me, at least as regards most posters not on the Fire Rocco bandwagon. It's not that we don't care, it's that we don't share the opinion it's highly important.
Let me ask you this. Here's an article that lists "somebody's" guess about prevailing MLB manager salaries and Rocco's name is missing. Craig Counsell set a record last year with a 5-year $40M contract, sourced elsewhere as well. Pedro Grifol ranked second, and he lost his job during this LOL-worthy ChiSox campaign. I can't find anything elsewhere either Rocco's salary, which may account for his absence from the list, but I assume it might be relatively high among managers, rather than lower than the $1M mark in this top-20 list, on the grounds of the Twins general reticence on topics like these.
Teams with aspirations for winning are, by contrast, willing to commit to contracts greater than $200M for players they think may make a difference. The Cubs are the first team, apparently, to be willing to commit even 20% of that for a manager.
I'm taking a stab at guessing Rocco made good money, about as much in 2024 as Carlos Santana, a thoroughly average major leaguer at this stage of his playing career.
Why would you suppose that is? The people rudely labeled as "Rocco supporters" seem to have an implicit view of the answer to that.