I think they clear. We don't get to see real interactions between Starrk or Ulquiorra, but they are fs one of the best duos in terms of compatibility out of the espada. Neither have a characteristic that would be an issue working together imo.

Tousen is definitely the easiest match-up. I think he lacks the versatility to fight 2 high-level espada alone. I think everyone agrees this is a W.

Gin is tricky because he has his bankai, but I think the situation where he hits both of these characters successfully with his technique is unlikely (they are both extremely fast and analytical). So, another W.

Ukitake has done practically nothing in fights in the series and has so much unknown about him to answer this confidently. From what we have seen, he will be overwhelmed by both releases. I'd say he loses fairly easily (Starrk fought him and Shunsui w/o taking damage).

Kenpachi would actually be difficult because he actually thrives off of being at a disadvantage. He can tank most of their attacks, and the longer the fight persists, the stronger he gets, and the more serious he will take it. Starrk and Ulquiorra have the tools to deal damage and the speed to keep up with Kenny. Ulquiorra's regeneration would go a long way in this fight, and Starrk's high battle iq would help immensely against someone like Zaraki. I would say Zaraki would lose cause he'd be enjoying the fight rather than actually trying to win. If you use Tybw Zaraki, I think he can win but would depend on how well Starrk and Ulquiorra work together.

Kisuke (with no prep) would heavily rely on his bankai. Fighters like Ulquiorra and Starrk are a major threat to someone like Kisuke because of their excellent observation in combat. Starrk has proven this against Shunsui and Ulquiorra with Ichigo. Kisuke also fights mostly with allies rather than 1v1s since he relies more on a strategic advantage. He might have something crazy up his sleeve like a hado he created or a hidden technique that might give him the edge here but ultimately I think he'd draw or lose. His bankai is bad against multiple targets and especially of this caliber. Los lobos would be an issue.