Maledom just mean the guy is dominant. The kink is in the attitude of the guy towards the girls, it doesn't have anything to do with any of his physical trait. Sure it usually goes with the guy having at least a decent size. However, the size here is fine and, most importantly, believable. If we're going into psychoanalysis territory, the "physical dominance" is established through the girls NOT having a cock and every other guy we see naked having smaller cocks maybe. That is enough to add the freudian fetish of power = cock association without the need to make the guy a freaking orc. Bigger than normal, but believable, is enough. The monster cocks we find in some VNs are so ridiculously big this is just laughable and doesn't add anything to the fetish of domination. Some can tolerate it, for me it can ruin a scene (and I'm sure I'm not the only one).
Gotta love talking about the sizes of cocks in VNs on the internet