I have no issue with signing Trey Flowers as long as we don't go silly on the contract, and in turn add players to that front seven to support him. It's like you say, we aren't one player away, we need more than that. But Flowers, at the right price, could be an important piece to the puzzle. He's still young and got his best years ahead. His addition could take the pressure off any new drafted players from needing to produce from the get go.
Also, the idea of a multi year rebuild is very much dependant on the quarterback. If we draft Haskins, Lock, Murray or Jones and they have a strong rookie year on the way to let's say 8-8, then it is all about adding depth to the supporting cast because our aim in year two would be to challenge for the play offs. So while we need to rebuild, the speed at which it occurs will be dependent on finding the next quarterback. Conversely, miss on the quarterback and the rebuild takes longer, and perhaps increases the odds of a high pick.