WOW I'm dumb. Thank you, Kikki, Sharance Maze...not Rune Prana.
As we can see, it's been years since I've played this game.

Dammit. For correction, I'm wondering if the Sharance Maze weapons are randomized, because you could grind in there.
Seed dungeons definitely got me through my second playthrough, all arcs. And I know I went into Sharance before I finished the game (both full playthroughs), so it's very doable.
The companions you get through the story are all you really NEED, but maybe go back and tame a couple of bosses for extra DPS?