I think Rivers, Ryan, and Dalton would have to accomplish a lot more to get in.
Rivers is the next Marino or Moon IMO; statistically superb but without a SB win. He is 8th in TDs, passer rating and completion % and 13th in yards. Obviously the yards and TDs will continue to look better. He is on the same level as Eli and Big Ben statistically just without the SB wins. His win % is similar to Eli's as well. I think at the end of the day he is in but likely not on the first couple of ballots.