1. JC and ZN have one more year under their belts. Like it or not, OL are rarely ready day 1 - physically or mentally. They both are over 300. Zion is now a backup instead of a starter. That's a big difference.
2. Williams solidifies one tackle spot.
3. Clark is now a backup instead of a starter.
4. Rivers is top notch and can spell in a pinch.
5. Ousman is coming in with JC expierience and is a very solid player (LSU wanted him).
The biggest difference to me is the backups. They are either game ready (physically) or had valuable experience last year.