The judoka would get his face broken with elbows....
If you isolate “the thai clinch”, and then try to impliment it into grappling it will not work because it’s founded on a certain set of rule. No lifting your opponent, no hip tosses, no reaping etc.... If you change the rules and use an oppo that has used them extensively, what do you think would happen? I say “the Thai clinch” as there is no separation between that and the striking component. Leaving your hips back leaves you open to knees through the center, hips in cup to cup leaves you prone to trip and throws, underhooks leave danger to elbows, removing aspects will remove its effectiveness.
A common thing you see in amature MT is guys reaching down to block knees with the forearms hips back, when the oppo had double collar tie (phlum). The reason they get away with it is because a key aspect is missing. The ability to smash the person in the face with elbows when both arms come down.
Another thing that needs to be understood is that although a throw is great, it’s no always the main aim. If I can trip an opponent and make him stumble, it’s 100% legal to kick him in the head on the way down. If I unbalance an opponent it means I have the opportunity to land strikes. If I throw he just gets back up, if I unbalance and strike I can cause damage