Nathan-
Okay, following you now - almost like this?
That being the case I would just pin his wrist to the ground and rotate my body while keeping pressure on the back of his tricep so that both arms are trapped, him facing you, you face down with your trauma plate on the back of his shoulder and his own body pinning the other arm. There are multiple neck restraints from this position, he can't hold onto you to keep you from disengaging, he can't bite you because his own arm is across his face, and he can't access weapons if you have enough pressure.
Here is BJJ black belt Marcio Feitosa setting up a choke, and doing what I mean:
You'd then either collapse the space, or get up and away.
This is also a follow on to the kesa gatame, if the guy tries to strike or gouge you with the free arm. I, too, don't like kesa gatame as a tactical osae waza, but if you end up there, you end up there.
If the guy gouges or strikes you, defend and take his wrist or sleeve. If he pushes you can actually go right into face down waki-gatame from here (Pascal Krieger just taught this at our dojo last month, though I missed it!).
Otherwise pull so that his own bicep goes across his face, and turn into him as above, you'll end up in the same position.
One of the greatest advantages of grappling is exactly in developing the "Art of the Transition," going with the flow of what the adversary does to trap him. The difference here is simply the end goal. The sportive versions involve either extracting arms or staying tied up to work in locks and chokes, whereas the tactical versions really only focus on his ability to be mobile, mount an effective attack, hold on/prevent you from disengaging, or access weapons. You can forestall many of these things all at the same time with many of these moves, which is why I often say that for real fighting where weapons and foul tactics are in play, the end goal is often found in the set up for a submission, but not the submission itself.