5-10 is a good place to get normal scrolls.  Need 4 horseshoes for hard mode. ★6 Rafina+9 (Kill 2, 3, 8, 9) ★5 Wiggle+9 (Kill 5, 6, 7)

40-10 is mainly for leveling up 1 merc, the last 9th spot.  However you can still get normal scrolls, and good amount of golds.  Need 8 horseshoes for hard mode.  When other 8 mercs are max level, 9th merc will get 6245 exp (781 exp / horseshoe) which is better than 45-10. ★6 Arines+9 ★6 Ebo...

25-10 is a good place to get normal scrolls, and leveling up for several mercs.  Need 6 horseshoes for hard mode.  Sometimes Angelica fails to land critical, and won't be able to one-shot the boss.  This formation is tuned for clearing as fast as possible, but you can replace Zakan, Chalkle, and Eun...

2, 3, 5, 7, 9 can be switched to other mercs, so you can include couple of mercs for leveling pretty easy here. ★6 Leto+9 (Important! Stun the boss all the time) ★6 Granhildr+3 (Any merc with Bebuff Immunity to block Concentrated Fire, but not necessary) ★6 Arines+9 ★5 Esther+9 (Kill d...