Sad reality as noted by Ken Adams
"Many lawyers have the notion that their firms or law departments have a consistent drafting style, hence the commonplace put-down: 'That's not the way we do things around here.' But it is in fact highly likely that any given organization exhibits a crazy quilt of drafting usages. Life would be simpler for the individual drafter and the organization if all drafting were done according to a house style."
Ken might have gone on to say that his own Manual of Style for Contract Drafting would be a good choice for a house style manual.