I personally believe there are not and prefer the Continental system (which I believe is used in most countries in the world) where the coach is the boss, and the manager seeks players under coach's requests, does the paperwork, looks for sponsorships, etc, without having absolutely nothing to do with team selection.
At country league level, it seems to me the manager is important in a kind of football where there's no attachment to team colours and players follow a person, rather than a club: manager goes, there go the players with him. Even here in the UK I'd give the coach the team control and make the manager an administrative figure only. Or else, the manager must be also the coach.