[starslayer]

If I recall UNCLE was ultimately really good at their job.

Infinity and Centrum agents might first learn about the organization when they wake up in a cell after being tranquilized and are questioned about their association with THRUSH.

UNCLE would likely not like infinity much once they got the whole story (what with the widespread abuse of worlds, allowing the ultra rich to dominate the poor to the point of manipulating them at fundamental levels), and would not like Centrum much either (single government body working for the good of all mankind- but also bad about widespread abuse, also slavery).

They would be horrified by the Cabal and the Nazi worlds, which would lead them to wanting to ally with one, or both groups.

Edit: I've since posting this taken a re-read of the centrum book, and I recind my thoughts that UNCLE would be on the fence about Centrum- their full dehumanization of offworlders, and use of slavery would exceed the goodwill from being a working post-scarcity society, and the top level manipulations of their elites would be really scary for a group trying to prevent hidden super-villains from controlling society.