I think it's going to come down to who is the most well rounded. Standing, it may be a wash due to Lyoto's awkward style and Rashad's precise striking and speed. I think they are both very intelligent fighters as well who can gameplan the best in the division.
I think it may come down to Lyoto's sprawl versus Rashad's takedown. Striking, I think I'd give Lyoto the edge if only because no one has ever gotten the upperhand on him there. Rashad's great, but it's hard to fight someone who has a unique striking style all to himself. But if Rashad can get past Lyoto's takedown defense and keep him down, he could very well win. We know Lyoto has ground skills, but outside of a few fights, he's never really needed it. His sprawl has kept Judoka's at bay rather easily, and Rashad's takedowns aren't really super elite level.