The basic genetics of it are the same, hops still follow the Mendelian model.
But one has to distinguish purebreed breeding and hybrid breeding. The first, as with the Holstein cattle example, aims to gradually weed out all deleterious alleles from the gene pool, counting on spontaneous mutations to yield novel traits, and propagating these among related breeding lines.
Hybrid breeding is different. Yes, you can start off purebred elite stock for your crosses, and that's generally a fairly good idea, but the intended goal is to benefit from heterosis. Instead of aiming to get all of the good alleles twice, you are aiming to pair different alleles that work well together, in synergy. Simulatenously, you are working to override any deleterious recessive gene previous inbreeding might have inadvertently left you with.
The thing with hops isn't that the theoretical basics are different, it's that, practically speaking, the premises aren't the same. With any livestock, you *can* use elite inbred breeders, because they exist, they are available. Starbucks is a famous bull, but you've got the same thing in other species, even non-mammals such as honey bees. In hops, these don't exist. Not because they are theoretically impossible, but because nobody ever bothered to do it. With animals and annual crops, you kind of have to make crosses at regular intervals, because your elite specimen will die of old age. Not so with perennials that are easy to clone. The best bulls of the 1800s are long, long dead. The best hops of the same years are still being grown today. And most of their offspring that are still coming out are not far off, being their daughters, or grand-daughters, but never their great-great-great-great-great-great-great-great-great-great-grand-daughter, because nobody bothered to make so many successive crosses. And nobody bothered to do it, because it was a lot of work, and there was no point to doing it. And the reason there's no point to doing it is that hybrid breeding schemes have worked just fine all this time.
Thus, males will definitely yield important traits. The problem though is that they are largely unknown/unknowable, because they are not purebred themselves. As such, the combinations each male can confer is huge. Especially given the same is applicable to the females, and thus, when you cross two hops together, there's a lot of variation in the end results. With large enough samples it's possible to try to deduce some things, and that was done with some of those USDA males, but it's still overall pretty generic.
The other aspect is that hop breeding is rather peculiar, in that it doesn't usually aim for specific agronomic traits, but aims for novelty, especially in the domain of aroma. Taste/aroma is practically absent from industrial breeding schemes, because it's impractical to breed for, and the consumer selects fruits based on appearance firstly, and the growers on yield firstly, so in many crops breeders just strive for something that yields quite a lot and that looks nice. But that's not the case of hops, which are an aroma crop, and which is in an industry that fuels on novelty. If you were breeding most other aroma crops, like thyme for example, then you could probably just set some parameters, such as thymol concentration and/or yield, and focus on such a quantitative trait. But that's less true with hops, where a lot of work is put just towards finding something that's "new". And in that sense, wild stock is gold, because looking for "new" in "old" is possible but less likely to give you what you are looking for.
But again, that's arbitrary. You need to adjust your breeding model according to what your own aims are. If you want a hop that's essentially a higher AA version of Tettnanger, then by all means, cross a Tettnanger with USDA 21110 Male, and perhaps then a sibling cross, and you might get exactly what you were aiming for.
