Is it possible that we're overlooking the obvious, here?
Here's my attempt at a process of elimination method decision point.
1) We have acute needs at QB, WR, LDE, and TE. And I do mean acute.
2) FA does not appear to offer realistic solutions to these 4 positions, so the draft must provide them.
3) Therefore, I do not favor trading up with valuable draft picks to get a Goff or a Wentz. Better short term and long term value in keeping the picks and getting starter quality players, I'm thinking.
Now we come to the second fork in this logic road...
Which players, realistically, will be sitting there at 15 for us?
If a QB (Lynch) is there and they feel he is clearly the best value/need player, take him.
But if a terrific WR (Treadwell) is clearly the best value/need player in their mind, then he should be the pick.
So it's more about which specific players are there, rather than which position has a higher value.
Remember two very possible factors in their thinking. They may feel that Treadwell is the safer pick in terms of his likely probability of success vs a QB. That's huge, imo. And they may also have their eye on another QB that they really consider a good fit and that they feel will be there in the 2nd round for them.
My point? Their draft strategy has multiple facets and is very nuanced.
Not unlike a chess game.