Yeah most of these "Champ team lineups" seek to think we're gonna literally sell almost every single first-teamer.
Bigger teams like West Ham and Newcastle that went down tended to keep a core of key, PL-standard players (Nolan, Guiterrez, Coloccini, etc). And unlike teams like Villa, Leeds and Leicester we're not a financial mess and wont be forced into a fire-sale of our entire squad. It would be a massive financial blow but not existential.
My guess is we'd sell high wage earners like Romero, VdV, Kudus, Xavi (or maybe loan a one-season loan to cover wages for Xavi for instance). Plus a few internationals with resale value like Rich, Dragusin, Vicario, Tel, Bentancur, Porro etc. Although expect 1 or 2 of the above to end up staying if/when clubs aren't willing to pay the asking price. Relegated clubs usually end up with a couple surprise players that get stuck.
Think we'd keep something like Gallagher, Solanke, Bergvall, Danso, Maddison, Gray, Sarr, Spence, Souza, Odobert and probably Kulusevski given he's seemingly perma-crocked. Bring back a few of the youngsters from loan (Moore, Vuskovic, Lankshear, etc). Basically a core of English players and talented youngsters.
Of the players still at the club we could put out something like:
Kinsky
Spence Danso Vuskovic Souza
Gallagher Bergvall
Kulu Maddison Moore
Solanke
With players like Odobert, Sarr, Gray, Takai, Lankshear, Devine, Phillips, Donley as bench options. Plus a few Champ-level signings in key areas (wings, goalkeeper, CM full-back).
Under the right manager and without a million injuries that squad should be very strong in the Championship, but would be highly dependent on a decent manager fixing our mentality and uniting the group.