Coombs
R is "Rice": elite signing who will start in a spinal position, prime age and league ready.
S is "Saliba": generational talent or physical freak in a spinal position, not necessarily ready to start, youth age (21 or under).
T is "Trossard": any age, league ready, not expected to start but may compete to start, not in a spinal position (so full backs and wingers basically).
My theory is we should very rarely sign players outside these profiles, and if we do we're blowing resources on "squad" signings who likely won't start. Vieira is a great example: very talented but he's physically way below par, too old, and has too much responsibility in a key role when he does play.
This is why I was pretty suss on Sesko as he would've been a "Rice" signing who wouldn't start. Calafiori looks a gamble to become a regular starter but he's young, versatile enough to play at left back, and the mooted fee is much less than a true "Rice". I'm still not too keen as it's a bit of a crapshoot, but I can see the merit.