Dude, Shaub is a 240lb 6'4" HW. There's no way he could cut to LHW without losing a ton of his muscle.
If he put on some more arm muscle/shoulder muscle he'd be one of the bigger HWs in the division - he already weighs more than JDS/Valesquez/Nog/Kongo/Crocop etc and he doesn't look as built as them.
I think Shaub was one of the few natural HWs on the show. I love this matchup and I think it's a great style vs style fight. No matter who wins I'll be happy - if Nelson or Shaub loses I predict SF will pick them up in a hurry.
You are correct Sir. Nelson would have an easier time making a cut to 205, all he would have to do is eat like a normal person.