You're misunderstanding what I said. I didn't suggest that you were asking the Dev to put this content into the game, just that you were suggesting he might, because one section of the game allows him to include all kinds of crazy content. In that one section of the game, anything is possible. But in the rest of the game, things follow much more realistic pathways, and that includes the content with Cassius and Hammer. Obviously there is some margin for exaggeration. Because Myriam having sex with Hammer in any capacity, would likely cause her more pain than pleasure. But nothing happens that is not actually possible.
Getting fucked by Hammer in the ass, would normally be pretty painful, and she'd probably be in considerable discomfort for days afterward ( which of course doesn't happen in the game). But because the rectum is so elastic ( I've previously pushed a very thick twelve inch dildo entirely into mine, so I know this for a fact, whereas that's impossible in my vagina), it's entirely within the bounds of possibility. Whereas, the female vagina ( which can stretch a lot at the entrance) narrows to a very thin entrance ( the cervix) before it enters the uterus. The cervix has a very limited elasticity, which is not a problem, because only a relatively small number of men are capable of reaching it with their penises, and only then (usually) with the very tips of their cocks.
Hammer however would totally rupture it, and cause severe internal bleeding, which would have almost certainly killed Myriam. Being a horse, he would follow his nature and hump away without restraint, which in normal circumstances wouldn't be an issue. Because the vagina of female horses are even more elastic than those of humans, and the horses cervix itself is more elastic, allowing the stallion to penetrate it without causing a rupture.
A human being like Cleavon for example, who has a much longer than average penis, and could potentially damage Myriam's cervix, is able to moderate his thrusts if necessary, so he doesn't fully penetrate her. Whereas Hammer can only do what his nature dictates.