Yes, aggression is the core emotion of dominance. How he regulates it is entirely irrelevant to how dominant he is - it will only impact how effective he is at obtaining it (and it won't impact him much negatively at all, he is seemingly physically all-powerful (30 might check what), has no laws like rape to worry about and is seemingly completely without compassion for the feelings of others (which makes sense, it is the core emotion of submission)).
Because of who Shaya is. She is a prostitute, she has had hundreds if not thousands of cocks up her quim. Swimming pools worth of spunk. Putting your mouth/tongue on that is utterly repulsive, imagine a sponge soaked in cum, an immensely submissive thing to do - akin to coprophilic ass eating. And, all for money.
Once a prostitute, always a prostitute - no one can come back from that. She is inherently worthless, damaged goods, disgusting. A beautiful looking toy to use, fuck and discard.
Not to mention the fact that Rowan has ZERO reason to give any fucks about her feelings at all. She is a complete stranger to him and a prostitute - she is simply a living onahole.
You cannot equate your previous example of hypothetical me with my hypothetical girlfriend/wife with your new example of Rowan and this stranger prostitute. There is ZERO overlap here, other than both examples involve two humans, one male and one female.
The only reason to care about the feelings of this prostitute stranger is if Rowan is driven by compassion, the submissives driving emotion.
I'd make the same mileage argument about Jez too but she seems to be almost a pure lesbomancer, so she kinda gets away with it. Not too sure on that though, I've seen almost 0 of her content having no interest in femdom.
Does it matter? I'd say B but practically there's not really much in it.
A is more of just a controlling personality, much of what you outline isn't sexual. His preference for dom is a function/offshoot of his overall desire to control everything. Or perhaps, his need to sexually dominate but not break the law expresses itself differently.
Whereas B is purely sexual, and seeing as we're talking about dom/sub in the sexual realm, he is therefore more dom.
Including everything sexual and non-sexual, A is more dominant.
Obviously in all of these examples willing consent is assumed.