It really does depend on how you view them and how you want their relationship to go. I think they almost definitely compliment each other in that Clark very badly wants validation that he can stay the way he is in the Backrooms, and Simon all things considered wouldn’t argue with him.

It really does depend on the scenario that you imagine them meeting in, and also how you want to view their relationship. I think if Simon were to (isekai’d style) noclip into the Backrooms after going into the blood ocean he would definitely be a lot more accepting of Clark’s views and stay there given that he’s 1. Freed 2. Alive. I do think at the start they would be very cute together, as Clark is getting what he wants and Simon is getting a much needed break from all the red, and being showed some really beautiful stuff of what Earth was like. His beliefs, like Clark, would be that the world surrounding him is amazing, and similarly to Clark wouldn’t have much morals regarding it. But, if Simon just stumbled upon the Backrooms and hadn’t been imprisoned, he almost definitely would be a lot more reluctant to agree to Clark, especially if Clark were to tie him up like he did for Mary.

What I mean by “how you want their relationship to go” or “how you do imagine their relationship” is that how they communicate with each other can be very different depending on how you see them and what point in their lives they meet (which is always the fickle thing with crossover ships). Probably near the end of both their stories I do think them meeting would be a happy ending, where they can both respectively heal. Clark gets his validation and Simon gets his kind-of freedom. But then the more you think about the situation the more it can kind of shift ?

Clark staying in the Backrooms only fuels his negative traits because “that’s how he’s wired” , and Simon, if held against his will for too long, will eventually begin to retaliate. Given their critical conditions it could lead to it being physical if the scenario goes on for too long, but I don’t (want to) think it would go so far as to say it would be abusive (as this is a comfort ship for me), but at the very least there will have to be a point in their relationship where it’s somewhat mutually toxic, and they’ll have to compromise to make the both of them happy.

I think at least from my perspective Clark would have to eventually get better for Simon, and Simon would have to… deal with his own issues and not feed into Clark’s need to be right.