Armed forces are a wildcard. If you manage to recruit a popular communist general, promote him to the max level and fire all more popular generals to get him into leadership of IG. The devout are very useful for passing public healthcare early, and then they are not helpful or worse. Rural folk can be very useful, if they get anarchist leaders. Petit bourgeois can rarely get someone good as a leader, but most often they are reactionary.

Also, I recommend passing Technocracy, because it allows to demarginalize Trade Unions much faster.