I would agree on the army comment. Normally, other than street patrols and emergency rescue...that would be the common work that the Guardsmen would perform.
I’ll suggest that the PR teamsters will be stupid enough to threaten the Guardsmen, and it’ll end up being arrest situations, and charges set up for threatening a federal officer.
Posse Comitatus authorizes the use of the regular Army in case of rebellion, insurrection and now per recent (2007, 2009 etc) changes, natural disasters.
I doubt the Reg Army troopers will be doing LE , but running ports, and convoys and reconstruction efforts is what our Engineer Forces do for a living.
PR ARNG will be involved in LE efforts and the whole of the rest of the effort, based on capabilities.
Oh, just for effect, the statues that direct the effort, the Stafford Act, prohibit any involvement of anyone acting with/in concert with the Army to mess with lawfully possessed arms, oh, I forgot, this is PR.....