I've spent virtually my entire career in medical sales & sales management. Very competitive, sometimes cutthroat, and I agree with a lot of what you wrote. One of my former CEOs used to similar. "The goal is to hire A-level sales people. You can sometimes coach and manage a B-level sales person to become an A-level performer, but you can never turn a C-level rep into a B-level performer. The sooner you recognize that, the quicker you can recover and retool."
Now, with that said, this corporate mindset would be completely different if sales reps were hired under 4-year contracts with lucrative buyout clauses. It would, in many cases, make financial sense to keep a C-level rep and allow them to maintain their sales territory provided they weren't doing harm and damaging relationships. For example, a C-level rep may only reach 85% of their annual sales quota, but if you had to buy them out and re-hire someone else (who carries the same unknowns as the outgoing rep), the potential benefit you'd get if they blow out there number at 110% to goal would be mitigated by the buyout you'd have to pay the outgoing rep + the risk of the new rep NOT achieving that level of performance.
The issue with keeping Rolo is that, given all of the negative PR surrounding his vaccine stance + the poor (so far) results on the field, he probably falls into the category of "doing harm and damaging relationships (recruiting/donors/etc). If he gets the vaccine, even at the 11th hour, WSU will probably keep him through next season. If he doesn't, then I can see him being placed on administrative leave and subsequently dismissed at seasons end.