As you say, to have a good go in the Europa League we'd need not only a bigger squad in terms of numbers, but one made of good players. Padding out the squad with dross is pointless.
The thing is though, where does the extra money come from?
Winning the conference league is worth about £19m. So basically, it'll pay for Canvot. And that's before wages are counted.
The Europa League is worth about £21m if you win it, though if course the real financial gains come from qualifying for the champions league as a result. We surely wouldn't be amongst the favourites to win it, though. Let's say we do really well and get to the last 8. We'd make about £15m. One half decent player, in other words.
If we win in Germany this month then the beauty of it will be a trophy (albeit a Mickey mouse one in my view) and the hope of seeing Palace in actual, meaningful European competition next year, against teams we've actually heard of, from the get-go. Maybe we'll get a big, memorable scalp. What won't be happening is Palace moving into some new world where we can carry a big squad of good players. The sums don't work for that.
Europe = premier league fatigue for anyone outside the big boys. Always has, always will.