It's not just a matter of him knowing a lot about the MD architecture. There's also the fact that, as I mentioned, he just seemed to be an all-around more effective, more consistent leader than Iizuka, who flip-flops on issues all the damn time, doesn't seem to understand what made the original 2D games fun, and makes controversial decisions like the "two worlds" thing that went into effect with Forces. I mean, say what you will about Yuji Naka's latter day games released under the Sonic Team umbrella, I think we can all agree there's no way Sonic the Hedgehog 4 would have ever released in the state it did had Naka still been at Sonic Team. But they could work with those games and possibly would if Naka were still around. The man coded Sonic's momentum based physics engine from scratch, don't you think he'd be interested in incorporating more 2D into Sonic Team's output after the success of Mania? I could be wrong, but I think he'd have a lot to say about those games and the lessons that should Modern Sonic should take from them.