Eh?
Wallace is at 4 mainly for defensive purpose. Esp if you consider the quality of attacking PFs in the draft. I can still somehow understand why some would say its not great. But whats wrong with the other two?
It's all good bringing in a defensive specialist to cater for the defensive end, but offensively, Wallace at PF would greatly limit your team (especially if you've got Hakeem in the low block orchestrating his Dream shake). He usually picks up his points via offensive rebounds or layoffs around the rim, otherwise he can't shoot to save his life, meaning you're playing 4v5
every time down the court. Additionally, just because he was DPOTY in the center position, doesn't mean you can simply slide him over to the PF position and expect him to play at the same level defensively. The likes of Aldridge, Barkley, Malone, Love etc would be far too quick for him and would set up away from the key and isolate him. He's far better defensively when he's guarding a lowpost specialist (probably would have given Duncan a tough time).
You've also got a player like Allen that thrives with movement around him that can offer him the space to operate (or the inches of space away from his defender that he needs to release his shot), something I just don't see happening with Kukoc and Wallace on your team. Obviously, you may have picked him due to his Seattle days as opposed to his Celtic days (where his gameplay and offensive role was different), but it's his sharpshooting that got him into the HOF, and though Hakeem may offer the double team threat that gives Allen the space to play his game, as long as Wallace is roaming the court opponents will have one less player to concern themselves with (and to double team off him)
Meanwhile, you've got Kukoc (an off the bench player, rather than a starter) that offers nothing defensively, and though he may have a nice shooting touch, he's arguably the worst SF of all the teams in this draft. He isn't quick enough to create his own shot, and fits far better on a smart moving everyone-touch-the-ball-offense (ala Spurs) than he does surrounded by Allen and Wallace.
Hakeem and Payton are a great fit, both defensively and offensively, but as I mentioned, that's pretty much the main threat and obstacle when facing your team. It's a good team you've picked, but taking in account the other teams in this draft, I'm just surprised you've made it so far.
In my opinion, Marc Gasol would have fit your team far better than Wallace. A Gasol/Hakeem/Allen/Payton combo would have made for a far more deadlier offense which would actually incorporate their playing styles perfectly.
But what the heck, you've made it to the finals, so what do I know!