A strategy I like to use for 2 QB drafting is taking a look at all available quarterbacks. Go down the list and select what quarterback would be the last one you'd be happy with as your QB2. Once you get to that player make sure you are allowing yourself to get a QB1 & QB2 at or above that line.

So for example- if you decided Mariota would be an acceptable QB2, but you weren't thrilled about too many after him then you want to make sure you are giving yourself the room to draft at least Mariota and someone above him. It all depends on what you would be happy drafting for a QB2. If you're happy with some of the later guys then there's not as big a rush to go back-to-back quarterback. But if think you may not get someone you'd be happy to start as your QB2 if you wait for your turn to come back then you may want to consider reaching for them.

I typically like to have both of my QB spots filled out by the 5th round, so I personally would probably go QB/QB. But if you went QB and maybe Gronk that would still probably be a good roster if you were ok with some of the later QB options.