Best Ski for Park + Eastcoast Icy Groomer Moguls :(

I just bought 183 Wet's with Pivot 12's mounted in the center for my first son who skis park. He's 6'2 and thin as a rail, and I went with the 183's instead of 189's so he can throw them around easier since he's just learning rails and mid-air spins.

Since we usually go with family and friends, the reality is that he'll only ski about 50-60% in the park. The rest of the time will be on black diamonds covered in 3' powder moguls with sheets of ice in-between. Gotta love the east coast. Even still, we're 100% confident this is the right setup for him.

He tried the Wet's out this weekend and immediately noticed it was more difficult to sink in an edge and carve. He even had to compensate for that while hard-stopping to throw up snow at his snowboarding brother whenever he was on the ground. I'm wondering if the lack of edging is more because of the center mount, or could it be the shape and flex of the skis? Or maybe the edge material?

I now have to buy skis for my third son, 6'3 and pretty thin. I would have gone with the same setup, but now I'm not so sure. While he will certainly do plenty of rails and jumps in the park, he'll never spend days-on-end perfecting nose butters. Instead, I think he'd care more about a ski that edges better on black diamonds covered in ice and moguls. That said, I really don't want to limit him from whatever he would do in the park.

If I thought the edging issue was mostly due to the center mount, then I'd probably just get him the Wet's and mount 10cm back and call it done.

So, any thoughts on how the Wet's would edge and carve if the bindings are mounted back more? Otherwise, what would be the best ski for Park + Eastcoast Icy Groomer Moguls :(

Thanks!