I want very much to rank Rivers higher than this, as I love Keenan Allen, Tyrell Williams and Hunter Henry, but Rivers can be inconsistent despite his great upside. He finished as the eighth fantasy quarterback last season, and his health has been amazing so far in this league. He'll be a player I draft often if his ADP lets me.
Goff showed good consistency and a nice ceiling against bad pass defenses in 2017. I think he will be a strong fantasy player in his second season with Sean McVay, and I have no qualms with him as a later-round starting fantasy quarterback.