De Gea, Valencia, Bailly, Matic, Pogba, Martial, Rashford & Lukaku.
Can also make arguments for a injury-free Jones (but you really shouldn't, because he won't ever be injury-free).
Add a 3rd high-quality midfielder / second striker / #10 and that midfield and attack with some coaching can do it.
We are in need for a new right back soon, and left back years ago, and a proper attacker from between midfield & up to the striker to link it all and provide some defensive help to Pogba & Matic.
The issue with the question from the get go is that it's not a first XI that wins the league, sure you need those qualities as well but you'll most often need the second-strings to be of high quality as well.
We currently lack 2-3 players for the first 11, but we also need to up the quality on our squad-players. People who will play when the main guys are tired or injured. If we had Griezmann for example, we'd still fall to Lingard when we do a change.
When Jones gets injured we're still down to Smalling/Rojo who aren't terrible defenders by any means, but they aren't good enough for that first XI spot through a season, and with how much Jones is injured we simply either have to Upgrade on Jones or on them (and it's much easier to upgrade one than two).
I think it's a major reasoning for why we don't play with both Rashford and Martial at the same time, having someone to throw in with qualities when it also gives the few quality players we have rotation makes sense.
We need upgrades on a few of Lingard/Mata/Mkhitaryan & maybe a proper right-winger to boot.
This is of course going by the "perfect template" picked out of my own arse without any sort of management knowledge or experience, so it's only meant for fun.