Experienced Starter w/First Big Contract
The more I've thought about it, the smarter it seems to me.
Of course, it's a gamble. The first gamble is to back your judgement. Is the guy you want good enough to be a long-term starter in the NFL with the ability to quarterback your team to a Championship? Say Mahomes or Wilson level. Or, if not quite that good, at least Watson or Prescott.
But let's say you're confident enough in your judgement to think that you've found someone at that level and the price is three first-rounders. Well, a franchise quarterback is going to cost you $25m. So, if you have your quarterback on a rookie contract, you can spend the difference on free agents. Do that arithmetic and going without a first-rounder for two more years looks pretty reasonable.
Here's the problem.
Imagine you made the case to get your guy (Shanahan for Mac) based on elite success with Cousins and Matt Ryan, and then AFTER giving up 3 first rounders, the franchise gets delusioned with Mac in favor of Trey Lance and you don't feel comfortable stopping the train. So you burn 3 firsts for a QB you didn't want 4 weeks ago....