Also I definitely got the feeling reading canon that Yuu and Sayaka were pretty compatible. They're really amicable for two people at odds in a love triangle, at least. Maybe I just have an active imagination.
I don’t think you’re imagining things, they do have a pretty good dynamic, I think precisely because neither of them has any reason to put up pretenses around the other. They can argue and have banter and be honest with each other in a way neither of them could do with Touko or their other friends.
I think it’s pretty telling in the third novel that the first person Sayaka brings Haru to meet is Yuu, and even Haru asked if they had history together lol.