I don't really know how else you could implement them except as a way of introducing flavor, at least in MP. In SP they can be used as they were IRL- to drop behind the enemy and occupy them/hold points until the heavies could come up from the beaches and support.
In MP? Assuming we're playing Wargame: Red Dragon: 1944 edition, they'd just have elite infantry... and that's it. Inferior in every other way (arty, towed weapons, armor, transport) to any other kind of formation, and they can't even fly around and flank/ spam millions of Hinds like they can in WRD.