The "he inherited this and that" is largely irrelevant - we're not talking about the season he came in, we're talking 10+ years later. Entirely his own team, with his own mindset.
There's many ways for a team to setup and win games against better sides - oddly enough Moyes himself was very good against City in the league. But not in any kind of relevant or cup game though, that's too dangerous.
Plan A was the way we played most often - down the left. If that doesn't work - Fellaini/big lad/Cahill or all 3 options in the box and pump it in.
Plan B - park the bus, clench the anus, hold on for dear life. Works sometimes. Oh also take a forward off for a defender.
2009 our plan was to defend for 90 minutes and offer absolutely nothing going forward - proper "park the bus there's 5 min left to go" game, despite the fact it was with an entire game to go as we scored the fastest goal ever at that point. Had nothing to do with money or who it was - if it was a League 2 team we'd still play that way, that was the only way to play in those situations. We've sat back and defended and it's cost us in cups to the point it was the "regular loss in the league/FA cup against a L1/Championship team" year by year.
Some examples though - 2018 Eintracht, having ridiculously inferior players to Bayern, played well, played on the counter, created chances, won the cup.
Leicester for the FA Cup vs Chelsea last year - shithoused a 1:0 thanks to a worldie, but didn't roll over.
Palace gave United a game in 2016 taking it to extra time, didn't roll over.
We just seemingly never could. Almost as if the way we set up was not "to try and win", but rather "not to lose". Had we beat Wigan and somehow miraculously defeated the giants of checks notes... Millwall... in the semi - we'd be absolutely battered by City anyway, by that logic, so why even try, right?
Also the 3 goals in a few minutes has happened so many times since that I don't believe you, but I also want to erase those moments, sadly lol
If you can't understand that there are ways to win against bigger teams - might as well just roll over to the "top 4" and let them have the master mega awesome super league or whatever the hell.
I just wanted to see us try in these competitions, maybe reach a final. Arsed what cup it is. Maybe it's me being salty the most "success" I've seen for us is essentially that same 2009 final which we had no bottle to try in and the Everton Cup or whatever for playing against Everton ffs.
Leicester won a title based on playing smart, not pretty, and by adopting an underdog kind of mentality against everyone. We can't over the span of 1 or 2 games though, as other teams have better players. Martinez was a beast in those - remember how we absolutely crapped on Wolfsburg? Remember how we finished 11th and we were on an obvious spiral, yet Wolfsburg were quite dominant and finished 2nd in the BuLi that same year and won the cup? KDB played in that game, Perisic, Bas Dost - yet, we dismantled them at ease.