I agree with your assessment about Hodge and Greenway in the Outback Bowl. Hodge just flat out had a better game. But, the reason he did was because UF is such a spread-out wide open offense under Meyer and that's not really Greenway's style even though he's pretty gifted in coverage. What Greenway showed is that he has to add a few tricks to his game if he wants to earn a nickel LB spot in this defense (as in he and Zach are the duo linebackers in the nickel package). He could obviously nail down the starting strong side spot, the question would then be how long until he's a player you can keep in on 3rd downs.
But Greenway is a huge man, a gifted athlete with incredible intensity and attitude, and he's got a very good nose for the ball going against more traditional offenses. He would be a no-brainer at #16, a stalwart on Saban's defense for many years.
Nonetheless, I think the Iowa-FL game and the Bama-TxTech game showed that if the Dolphins had a choice between Demeco Ryans and Chad Greenway, they'd damn well better consider taking Demeco over Chad despite size differences. Ryans had a similar task against TxTech, which is to say he was facing a spread offense that is not favorable toward linebackers. Against the spread usually if the D is going to take over it has to be led by the DL and the DBs. But Ryans positively impacted the game anyway by putting pressure on Cody Hodges in blitz, being a very good spy on the surprisingly fast Hodges when he scrambles, and in coverage. Ryans was a big reason why Bama held TxTech the way they did. I feel like Ryans is a guy that could nail down the starting strong side spot as a rookie, also be a nickel LB, and when Zach eventually leaves or retires, and Channing moves to middle, Demeco could move to the weak side...then we'd have to get another strong side guy.