Can also do it with 2 MMA and 1 MG with around 450R loss
A guild member told us,
you send both MMA with 220R straight to tower, leave a few mins before you send the MG with 20R 250XB (as both the MMA leave just the witch to kill in the tower) and the MG kills 10-15R to finish the witch, AGAIN not full XP as it is fast guide