I think this is a big question and important question going forward, just like you mentioned. There are several questions inside of your post of course, here are some of my thoughts:
1. Yes, Dotson is better than Avila but only by a slim margin. According to PFF Dotson was the #3 guard in the NFL while Avila was #9. I also think that this is probably true when I watched the games last year. I mean that the PFF grades match what my eyes saw. So, it's a toss up in my opinion for resigning because I think Avila still does have upside in him, whereas Dotson is probably at his peak. So do you sign Dotson for a 3 year contract or do you lock up a younger Avila with even more potential with a longer term contract?
2. RT is pretty much set with McClendon. I have to admit that McClendon really improved leaps and bounds over the course of the season according to my eye-balls anyway.
3. LT is a bit of a question mark going forward because of his legal issues and blood clots. For the legal issues the accusation has already been dropped from felony charges to a misdemeanor charge. I think in the long run this means that Jackson plays this year, minus 2 games or something like this. Even this hurts of course but are you going to go out and get somebody better than Jackson because of this? I don't think so. However, for next year the Rams might say "enough is a enough" and try to replace him. This is already the 2nd time this type of incident has happened, so he is obviously not hanging out with the "right" kind of people.
4. And finally, everyone's bugaboo, the center position. Shelton is a very reliable center, he's also a good line play caller or adjuster, but as for overall grade he is very mediocre. Will the Rams try to upgrade this position going forward? I doubt it really, the salary cap calls for a reliable mediocre center, that's all. It's just the Rams blueprint at this position. By the way, he was rated as the 13th best center in 2025 by PFF. Pretty middle of the pack.
