Cleverly, all 6 dungeons provide 50 mythos, though.

I haven't had to run dungeons for soldieries in weeks. Just doing the main 2 roulettes (Trial and High level) for the lovely mythos ends up capping my soldieries well before the end of the week.

I do run a bunch of the new dungeons to help FC mates cap their soldieries, and I love the higher level gear drops from there. Personally, I am very happy that all 8 level 50 dungeons are still kinda relevant (I get plenty of WP and AK from roulette runs, so I don't actually queue for those on my own, short of working on a new relic)