Well, this is the way I look at it.....McVay coveted Cooks, felt he was a perfect fit for the offense, so I won't pay attention to the contract as many Rams are due paydays I will allude to that later. Cooks is similar to DeSean Jackson, but a better overall receiver as Cooks has the ability to stretch the field and make difficult catches in traffic, so that is the player McVay coveted, he signed off on tagging Joyner over Watkins, keep that in mind.
Some will make the claim that Watkins is more physical, but let's not forget Sammy seem to struggle with some of the routes and his durability, with the exception of last season has been an issue, Cooks has not had that issue. The Los Angeles Rams are trying to win the Super Bowl next season nothing wrong with that and with the fact that Cooks is a California Native and has the same agent as Jared Goff also factors in for the long term and IMO, I feel that Rams think they will be able to keep him, however, it only takes one team to overpay to make that plan go awry.
McVay's offense is predicated on the deep ball, the Patriots offense is more short passes going across the middle, setting picks and moving the chains, McVay loves taking his shots down the field, so one could surmise that McVay's offense is a better fit for Cooks and now the Rams don't have to worry trying to draft a WR in a draft class that does not have an extensive list of high profile players, however, giving up draft capital does have its downfalls.
Great example last season the Rams tried to include Trumaine Johnson in a deal for Cooks, however, the Saints decided to take a first round pick from the Patriots instead, which was 32nd overall and then drafted CB Marshon Lattimore (with their pick 11th) and are better off with a rookie contract for Lattimore, then they would have been making the deal for Johnson so there is always that risk and the Rams must hit on their secondary selections without a 1st and 2nd round pick, the Rams with all of their 4th's and 6th's must come away with an edge rusher, ILB and OL depth because you can't count on the offensive line being injury free like last season.
Overall I do believe that Cooks and Goff will have a better chemistry than Watkins and Goff did,for whatever reason, that bond never existed as it was obvious when Goff was pressed, he looked for Woods or Kupp. Really wanted to win a playoff game last season to get that monkey off our back, however, barring injury the Los Angeles Rams appear to be set up for success this season and Gentlemen, it's not our money, so hopefully, the Rams can keep this core intact and provide all of us a consistent winner, year in and year out as all of us Ram fans truly deserve.