Another thought.
Who gets to decide who are the "Minnows" or under what criteria you're judged as such.
There's probably Clubs in the Championship that regard us as Minnows or have already placed us in "the likes of" category.
I'm sure a plum 3rd Round FA Cup draw would see us described as underdogs enjoying our Cup Final despite only being a League behind the top Clubs.
Look how England struggled to impress against the minnows that are Malta.
I guess you'd do it the same way that coefficients are decided. Perhaps the clubs in the fourth tier of the Nations League might need to pre-qualify for instance.
It works reasonably well in qualifying rounds for European club competitions - the clubs from the smallest nations play each other in the early rounds, and are gradually filtered out as the qualifying process progresses. And sometimes minnows make it all the way to the real thing: there's a Faroese club in the Europa Conference League group stages these year. A well-coached small team will always be able to give a respectable account of itself. But they don't have to compete on a level playing field with Bayern Munich and Manchester City right from the start.
It's not a perfect comparison because there are many more clubs than nations, but it shows that it's doable.