Agreed, although I believe that of the big three at QB, the one with the highest upside this year is Brady. Since its a full PPR, Megatron gives you a great advantage, but I think thats a little early for him. If you draft a QB, it is imperative you come back with a RB in the next round. Also, I don't know the people of your league, but do not automatically assume that at 4, you will not have a chance at on of the 3 rbs. Maybe not in the most experienced of leagues, but outside of that in live drafts there are always people willing to reach for someone they like or someone who did well for them the previous year. In my draft which is a 6pt .5ppr this was the order of the first 6 picks(I was #3)
All you need is for one of the 3 ahead of you to pick a QB, and you will be golden with a stud RB. I think it's wise to prepare for that possibility as well.