Let's assume BYU adds 10-15 guys to the roster via the portal. Just trying to sort out priorities, here are my Plan A & Plan B scenarios for each position:

QB
A: A high level but unproven talent with 2-3 years of eligibility remaining
B: A 1 year rental who fits the system & is a clear upgrade over the current group

DL
A: Two Day 1 starters
B: 3 or 4 effective bodies to add to the 2-Deep

OL
A: 2 or 3 starters regardless of remaining eligibility
B: 3 or 4 additions overall to the 2-Deep

S
A: An immediate impact grad transfer starter
B: Two P5 level effective depth pieces

CB(2)
A: 1 Alpha grad transfer, 1 starting caliber player with 2+ years of eligibility
B: 2 depth pieces for the 2-Deep

LB
A: An alpha to lead the young group if Bywater is not returning
B: 2-3 guys to fill out the 2-Deep as starters or high level contributors

TE
A: A clear #1 receiving threat from the TE spot regardless of eligibility
B: An unproven but talented receiving threat with 2+ yrs of eligibility capable of complimenting Bowers

RB
A: If Robbins leaves, a legit #2 who can carry the load alongside LJ
B: If Robbins stays, a speed back who can threaten the edge as a runner & receiver

WR
A: A speedster to take the top off the defense
B: A true hands guy to reliably move the chains on 3rd Down

ST: None