My inner completionist demands I get all my "unused" DoW/M classes from ~30 to 40 for no real reason other than it looking nicer (and being the next step in getting them all to 50 eventually where more options open up) and freeing up some retainer space.
I'm looking at mostly DPS, the one healer I can't quite wrap my head around (AST) and two tanks I refuse to play in dungeons.

I suppose I'll get AST done through dungeons so that leaves DPS with 15-30 minutes queues and the tanks where I'll skip dungeons alltogether, I'm done being hurried along by DF DPS when I already feel insecure about setting the pace.
So, to get to the point, what's the fastest way to get those from 30 to 40, squads?