The Suns didn't fail because they traded for KD and gutted their wing depth, but rather because they sold low on Ayton and traded away CP3, the player who supported the team's floor, to acquire Beal. If Dallas wants to replicate that model, they still have Lively and AD. I don’t believe Irving, who's likely out for the next season, will re-sign with a Dallas team that no longer has Luka. I think Dallas has the strongest incentive to take on Beal while going all-in on KD with their remaining assets.
The Rockets have swap rights for Dallas’ and Phoenix’s 2029 picks. Gutting Dallas' bench depth might be more valuable than a straight-up trade for KD. These assets are easier to convert into draft picks than KD.