I suppose that depends on what you think those holdings represent. IMO, law support captures the support of the aristocracy and lesser nobility of a society. The only way to remove that militarily would be to massacre the aristocracy -- which would have far broader casualties than the nobles themselves. Likewise, guilds don't represent store fronts. They represent large swaths of apprentices, journeymen, master Craftsmen, and the like. Militarily destroying guilds would require massacring 100s of people. Clergy are only a very small part of a church. The regular faithful exert most of the influence of a church. Again, would require massacring 100s of people.
Driving down holdings militarily requires massacres, and the only mechanic that really captures that is pillage province.