If your house memebers are also castle leve25, 55 will be really tough to fast clear. 45 and 55 are the stages you get perfec,when you reach 75.
If you have 30-40 lv house members, borrow lv 10-13 2xbows, 1turtle, and your gold units will be able to get perfect, i reccomnend gold horses and archers.