There's a difference between not trusting the manager and go full FM every time the manager asks you to do. United spent 200m last year and yet he seem to have come out with yet another list that could easily top the 200m mark again. That's financially not feasible especially during a covid crisis.
Let's make a distinction between coaching and recruitment for a moment here. I don't think Ole's a brilliant coach per se, but I do think his signings are good. If the board aren't convinced with his coaching, they should have sacked him. If recruitment was limited by a budget - they should have achieved at least one of his targets. You cannot half heartedly give him players he didn't really want because you didn't really believe he is a good coach. He is going to do worse as a coach with second-choice players making it a toxic spiral.
For what it's worth, I think Maguire, AWB, Bruno are all good signings. It's not Ole's fault that Harry Maguire cost 80m; he's not a Tier 1 defender on the level of VVD/Laporte/Lenglet/Varane at for that price point - but he is not as terrible as the last couple of games have indicated, either. It's too early to write off AWB as well; he can be effective going forward if coached better and given more time. Sometimes people forget he's just 22 and is a defensive beast - he pocketed Sterling, Mane, Son, Zaha multiple times last year. Bruno needs no defense, and Dan James was a punt anyways who's struggling with decision making and confidence and needs time to grow. Over the last season, Maguire/AWB/Bruno have all looked like decent upgrades under Ole. That is progress, no matter how much the board spent on them.
This summer, Ole didn't ask for replacements for his previous signings - he asked for complements. He also didn't ask for 200m - we didn't need to get all his first choice signings, even one would have been a massive upgrade. Along with Cavani, if we had signed only Grealish or Upamecano - it would still have been a very good window. He wanted to address glaring squad weaknesses with clearly well-suited, gettable signings. I don't see anything wrong with that.
Just ask yourself these simple questions. Do we need Sancho not to look silly against Palace and Spurs? Is our 130m investment in defence not enough to avoid conceding 11 goals against minion teams?
The first three games of the season are too early to pass judgements. Yes, the players were terrible, and the manager didn't cover himself in glory - but let's see how the rest of the season goes before coming to conclusions. Also, this Spurs with Jose and their transfer window are not a 'minion' team. They will finish above Chelsea, IMO.
Regarding your list of players well Valencia was old and he left for free, Periera went on loan, Young had a half decent season with Inter, Herrera left and neither club nor manager wanted him to leave, Lukaku and Smalling were stellar in the Serie A but according to Ole they weren't good enough for United (ie the same man who gave his go ahead to 80m signing Maguire).
Their quality or effectiveness is not the point. The point is the club let go of a lot of players who were playing a lot of minutes when here and clearly needed to be replaced. The point is that by doing so, we actually reduced our wage bill, thanks to Ole's decisions.
Meanwhile not one but two players (Lukaku and Sanchez) highlighted that there's something is wrong about training at United and if rumours are true VDB is already regretting coming to United. Not to forget that there's a tendency that new players start well only to perform poorly after a couple of months here. Which makes you wonder what the feck is happening at Carrington. Is Ole and his pack of very inexperienced mates at the coaching team good enough? Cause sure as hell we can't expect the club to buy 200m rated players year in year out to replace the ones our coaching team had burnt.
Again, distinction between coaching and recruitment - Ole should do better at coaching Maguire or Bruno or AWB (he has admitted to as much in his pressers), but he wasn't wrong in getting Maguire or Bruno or AWB. We were committing to transition under Ole before moving on to a better manager - while it was seemingly well done on the youth level, but will not work if you dont' back Ole's plan for the transition with players he considers inferior to his primary targets.
My argument is that the board needs to have clarity with what they're getting with Ole. He's getting players in with the right ability and attitude and he gets them to play decent football in bursts. Recruitment is his strong suit - he's building the core of the club with players who fit in and a building a culture that can be sustained. Then the next manager is chosen in a way that he can maximize the peformances out of these lads with minimal changes. Ole's not the best at getting his squad to do better than the sum of their parts, but the board knew that already and cannot keep using it as a defense for their own failings to procure his targets. You either back him or you sack him.