I think the only times Diego has looked shitty was whenever his opponent tried to keep the fight standing. Hughes isn't known for this, and would take Diego down, and IMO that's where Diego would outmatch Hughes. Diego is a much better submission artist than hughes, and a better all around grappler. Not a better wrestler, but a much better grappler. Diego wins in very similar fashion to his fight with Karo IMO.
Abashed the Devil stood and felt how awful goodness is...