The "FB" in McVay's offense has been a group lift (i.e. wideouts are involved there) and Skow did a really nice job in that role for us last year. He's a bigger body than Woods and we may see him moved around in a TE/FB type look if they expand him that role.
In other words Higs would be the inline balanced TE. Then Skow moves around. He's big enough to do that job, fast enough as well, and has good hands for a "fullback."
Benny is just a good all around player who will get dirty and do what is required. Which is great to have as long as you're not paying him. McVay will probably adjust his scheme to having that piece. We probably won't ever have a conventional lead blocker but that's ok when your staff is drawing up lead blocks by a more mobile group of receivers and btw both Kupp and Robinson are loads in that usage even though you don't want to do that ideally and risk them too much.