They are very good combat and transport mounts. The males can attack, which allows them to gather thatch very efficiently. The females have no attack, but are a little faster, as there are no horns to weigh them down. There's also something satisfying about riding a moose. WHEEEEEEEEEE
Best to bola them near the shore of the arctic region. Keep pumping narcotic into them as you can run to your boat with warm campfires and then run back. Wait a bit recover health, stamina hunger, etc, then go back to the megaloceros.