I started a new game today and I just picked that standard party (Soldier/Pilgrim/Wizard), and I have considered upgrading my party like this, not counting the Sage class:
Soldier > Fighter
Pilgrim > Wizard
Wizard > Pilgrim
In theory this seems to me like a pretty good idea, since it should let my endurable Soldier become a very fast Fighter and give both my wizards each others' spells, essentially turning them into something that should resemble Sages.
But this might not be the way it actually works in the game, so, any advice?