I'm not a fan of ranking QBs or HCs linearly like this anyway. Like with Dak, the only question I care about is 'can I win a championship with this guy or not.' There's too much variation between markets and divisions to be able to list 'Best HCs from 1-32.' The job in Dallas, for example, is a much bigger job than the one in Jacksonville, for example. The media spotlight, the commitments, the the interference level of the owners, the attention given to the players when they screw up or not, all that stuff is orders of magnitude bigger in Dallas.
And I know almost nobody agrees, but I think this Cowboys team has done enough right that they can compete for world championships right now, with this HC and this QB. That's all that really matters to me. If there's a chance to clearly upgrade either position, I'm all for it. I just don't see a lot of opportunity to do that right now, and I otherwise like where we are.