[quote=@Sadu]
I just figured everyone should eventually group up somewhere, and figure out a plan for their journey, why they are going on it, all that. Merlin would be the one to tell them 'So yeah, everything's really bad out there and we need help' and it'd be up to everyone as to where they want to go to help, to seal off worlds from the darkness, since that's the main goal of the first game and the reason they will travel from world to world. 
[/quote]

I think that's also pretty much what their companions are for. Hoshi has Leon and Launchpad, Lucian and Morgan(?) have Donald and Goofy, Levi has Zac, and Taivas have Dotty and Zen-Aku. They don't really have a reason to go to Merlin's but they can all meet up at the First District as they're leaving. The others still don't even know Hoshi and Morgan are there. Plus with Alias being MIA at least Levi and Hoshi would be focused on finding him and Kitsu.