Murray may not even play this year. Word is that they already regret giving him that deal. Jones could come in on a rookie contract and offset the massive mistake of Murray's deal.
And you do not know that McDaniels wanted Garoppolo over Jones. Garoppolo was available. And he got a three year deal below market value that they can get out of after the first year. That doesn't sound like McDaniels got "the QB they wanted". Looking at his contract, Garoppolo is the QB for right now, not necessarily for the future or even next year. And I think the Raiders may find out that Jimmy was more of a product of the Shanahan system.
And you don't know if the 49ers wouldn't touch Mac. In fact, Shanahan reported wanted Mac and was talked out of it. After two years, he would probably be happy to trade Lance for Jones straight up.
And I am talking about Jones with the only year we can evaluate the guy. And he was definitely a top half of the league QB. Unfortunately, because of Belichick and Patricia, there is no way we can properly evaluate the guy from last year.