If Mike Sherman is enamored of Ryan Tannehill, this guess is null and void. If he's not, then I think the early rounds of the draft might go like this: (I'm not a big college fan, so I don't have names for the picks, just positions and a QB name):
1. The best pass rusher on the board at #8:
2. Brandon Weeden - I can handle a QB that has the potential for a good 7-10 year career:
and 3. The best O-lineman left, probably a tackle but could be a guard.
I guess to delve deeper into your thought process, A & O, you are saying that if Weeden is not a fit, then that raises the stakes on what we should be willing to pay for Tannehill or that that means that Tannehill is a must.
But wouldn't it necessarily if we say that we won't get Luck or RG and the next choice after Tannehill, Weeden does not fit our system and we really need to draft a Franchise QB, then does not that put us into a situation wherein we have to trade up for Tannehill to make sure?
[Of course, I think it would be nice to get a QB and would settle for Weeden but in no way would either draft Tannehill at 8 and certainly not trade up for him].