Couple things here. Dotson had one really good year. His time in Pittsburg cost us only a 5th and they thought so little of him they upgraded the position with Isaiah Seminola from the Jets.
There a bunch of other cheaper guards that are just as good - Hunt, and Zeitler come to mind, and will cost less. Sure we want continuity but not having the $ to use on an extra FA.
In terms of Shelton there are better options period out there could care less if he walks. Wake link on the OL we need an upgrade.
BTW these stupid agents and players get offers that are a couple mil higher and they think that is the smart move. The smart move is to stay with a great organization and take a little less "home town discount", insuring most likely a longer better career - look at Corbett, OBJ, Johnson, Von etc they all thought, they were so smart and then their career dies or is devalued way sooner than anticipated instead of staying with a premier team. Robinson was smart and his career excluding injuries will have extended longevity.
Dotson knows the Rams want him the Rams should say we resurrected your mediocre career into a elite RG show some respect for the team that got you there. Instead he will go to a shit team and will look like shit and get cut after a couple of mediocre years.