That plan has worked once in 5 seasons for the Lakers.
I'd get the guy I can now, not court dudes I am not sure I have a shot at.
The only way that really makes sense is if Magic already knows someone is coming.
If not, then like PG13 or LeBron his first two trips through FA it could leave that team holding the bag.
Again, there is a penalty to pay in team building for operating far under the cap.
You have ~41M is cap space BUT ~44M in cap holds.
Kentavious Caldwell-Pope 26 SG
$15,600,000
Rajon Rondo 33 PG
$10,800,000
Lance Stephenson 28 SG Non-Bird $5,338,800
Michael Beasley 30 SF
$4,200,000
Ivica Zubac 22 C
$1,931,189
Tyson Chandler 36 C Non-Bird $1,618,486
JaVale McGee 31 C
$1,588,231
Plus you eat basically 1M per slot.
That's a lot of dudes to let walk for zero in return to bid one max slot.
And as good as Klay and KD are, the entire squad would be wings.
Not really ideal team building at all.
PG(limit turnovers; hit free throws) and OC(rebounding and rim protection) are still critical positions.
If you could move say KCP, Lonzo, a future 1st now you ensure a guy you want, free up Lonzo's cap hit and the R1 cap hit for a kid who likely won't touch the floor.
If Klay or KD are dead set on being Lakers you don't have to operate under the cap for 2 full years to get them.
You can trade guys at any point. Hard to win if you end up in free agency signing Beasley's and Stephenson types again.