So, JetBlue, Delta, RAH and Envoy (Eagle) all have a former F&H in-house - anyone else?

Just about everyone else has F&H on retainer, especially for bankruptcies, terminations, and, of course, negotiations.

Is there another firm that approaches F&H in terms of always being the adversary to pilots?

If airline management universally uses F&H, why don't pilots universally have the same level of resource? ALPA legal is probably the closest thing to it, but I have a feeling 'Airline Management Central forums' doesn't have a thread on how much they despise a particular attorney representing pilot labor.