No, I'm tracking with you, and you've made me think about how I "know" the recommendation to double overhand through warmups until switching to hook/ alternate. Background information through SS:BBT, and I think someone mentioned the Grip Problem article, matches personal experience. DOH warmups, though, will allow one to coarsely keep track of any improvements in grip strength.
With all hook all the time, I would agree that hook grip strength increases as one's deadlift goes up. My default hypothesis based on the background information though is that the DOH lifter's finger flexion strength would be greater than the all-hook lifter's. And that would carry over into a higher limit grip.
But there could in principle be empirical evidence against that hypothesis.