The Cavs really needed a "3+D" type as starting SG.
I do not think Waiters is well suited to that starting lineup. Too high usage. Cavs already have three prolific offensive players in Kyrie, LeBron and K-Love in the lineup already. Adding a fourth like Waiters will cause more problems than solutions. Waiters much better off as their 6th man and main offensive creator off the bench.
Ray Allen is a defensive liability. Putting him in starting lineup puts too much pressure on LeBron to maintain Cavs perimeter defense. Their interior defense is not top drawer either (K-Love, Varejao) so liabilities like Ray on the perimeter are a serious problem. Ray also best suited to that bench role as backup SG due to bad defense.
Then there is Mike Miller who is backup SF/SG (also defensive liability) and Shawn Marion (too old to play guard, not good enough shooter) who is backup SF/PF and Tristan Thompson (PF) or Varejao (C/PF). Not enough playing time for everyone. And still no good option at starting SG to complete starting lineup.
Need a Danny Green type of guy. Or even a Brandon Rush type (non-dribbler, non-passer) which would be fine since LeBron is such a gifted ball-handler and playmaker.