It is tough to find a year where this many QBs will go in the first but here are some comparables:
2012 - 4 QBs went in 1st, the 5th and 6th were Osweiler and Russell Wilson.
2011- 4 QBs went in 1st, the 5th and 6th were Dalton and Kaep.
2004- 4 QBs went in 1st, the 5th and 6th were Shaub and Luke McCown.
In this instance where so many QBs are drafted early, there is obviously less chance of the guy you drafting being great. In this situation, it would suck to get the guy that turned out bad, but at least if you take both, you would have got a good QB.