Hard to tell with such adept liars, but Evrart's admission (if you want to take it as such) to Harry that his ultimate goal is to take everything from the capitalists of Revachol, always struck me as at least partially sincere.

Supposing that they are genuine socialists, that isn't going to automatically make them nice men. Quite the opposite, most major historical figures weren't nice people. Even heroes like Lenin and Stalin had hands that were far from clean; the Tiflis bank robbery is just one example of the kind of tactics they were known to resort to. I've heard the term "gangster socialism" used to facetiously describe the Bolsheviks' early activities. If you believe the Claires are true comrades, then they're also undoubtedly practicioners of gangster socialism par excellence.