Literally the only problem with this scenario is that it's unlikely to happen
I agree that it's unlikely.
Honestly, the most unlikely part is that Lebron specifically wanting to come back to Cleveland. If he just wants to win a championship this year, he should ask for a trade (the Lakers aren't going to be that good) -- but he should try to go to like: Miami/Brooklyn (if KD stays)/Milwaukee/GS instead of Cleveland. We're really too young to be an optimal choice for this season, even if we are overperforming.