It's true that I think we have to temper what is actually possible with these players. Maybe nobody can would do substantially better in terms of actually competing for major honours, almost certainly true in fact, but probably a stretch to imagine nobody could have done any better for example. He's just one man of many good managers, no reason to suspect he has done the best that is possible, especially in the league and our dire CL campaign. So his performance could well be somewhere in between.
The issue for me is he has done things and continues to do things which really hurt his credibility to say this is the main we go forward with. What would we grasp onto as an owner to feel confidence about that? For me saying "who are the other candidates" is not reason enough, I would want to know the reasons why ETH is to remain too, he can't survive by default.
Strange tactical setups despite the same consistent leaks in our game. Nonsensical handling of the press which doesn't lend him much credibility or authority, that stuff does matter as a figurehead for the club. Odd signings which while this won't be his primary responsibility going forward do raise questions about some of his judgement. A couple of years of treading water and the players hearing that same voice associated with it, it could well be that a new voice is sufficient enough justification. I think a new manager alongside new owners that have chosen him is better rationale versus same manager by default just because there isn't a candidate leaping off the page.