So did they ever showed how you actually enter missions and swap between regions?
Is it really like Monster Hunter? The village would be like a hub, and when you talk with someone to accept a quest, you can start the mission, which teleports you to the mission map
On MH Rise there's just one village that teleports you to any map
On MHGU there's one village in each region, and you just teleport between then IIRC to then accept a quest from a map from there
Arceus' maps look bigger and more open than the MH ones though, so maybe there's a bit more focus on exploration, and maybe more objectives in a single session