I think you're looking at it all wrong.
Frank isn't going to win the league. Or the CL.
But 99.9% of the managers we employ aren't either.
Nor is Ange.
We just need to be better than last season.
Frank is a better all round coach than Ange, and I have no doubt, if given the grace Ange was, could have won the Europa league with us as well.
We as a club might need to play chess a bit here and think a few steps ahead. Frank to get us back up to being a top 5/6 team every season.
That's the first step. Then you look at a coach who can push on that little bit further, maybe top 3 and good shot at cups.
And then, if we have managed that for 5-6 years, you go for, and successfully attract, a generational coach.