Mexican drug cartel perhaps???
Everything seems to fit if Paddock was a bag man for a drug outfit (and possibly an LE informant).
He’s an accountant, owner planes in the past, rented BnB’s for meeting.
That said, he had a gambling habit, extremely dangerous hobby if you handling large sums of cartel cash. Did he lose more than his cut, worse did he try to win it back?
Did he miss his scheduled drop, fearing his house would be ransacked he took all the guns with him?
Was he caught and became an informant. He could have been facing an uncertain future. If nothing, he would know high roller lifestyle would be coming to an end, add disgrace to that => resentment!
The arms dealer thing, while sexy, just doesn’t fly.
The same occurred to me. Could be.
There seems to be ideology in the mix though, given the crowd were patriots.