This should be a good fight. One of Diegos problems is that his takedowns are not that good. Against certain fighters he could have trouble getting them to the ground where he really shines, and it would be a stand up fight where it could go either way.
Guida has no stand up and wants it on the ground so I hope this stands into a ground war. Diego is a better scrambler and has better submissions and Guida is just a straight grinder who never stops pressuring. I think Diego will be too much for Guida both on the feet on the ground but I hope it takes place mainly on the ground.