You can't have a system that literally depends on the fasted player in Europe to function. Yes, if Porro, Romero, VDV, Udogie was fit for every game, plus we bought a Rodri level #6, plus an elite LW, Ange might win the league, but that just isn't realistic.
The way we win the league under ENIC is the same way any of Arsenal (who fudged up their chances), Chelsea, Saudi Sportswashing Machine do, build as good a side as you can, and hope to take advantage of an off season by City/Pool.
Ange understands tactics, he just hasn't accepted the ceiling of his, for 29+ years his system has worked, and doubling down each time has paid off. The issue is at the PL level, it's been found out, opposition teams are tactically aware enough to counter, and capable of converting at a rate that the number of chances his system gives up is not sustainable. The fact that we won the EL by playing a completely different formation and by focusing on not conceding vs outscoring opponent (especially in last 4 games), shows regardless of if he admits it or not (or like your argument, if I had a few less injuries or 1 or 2 better players, it would work), the system has a ceiling.