most of the critter packs are offered with way too many cleaners for the size tank that they mention it is good for. i have seen some of them that say 100 scarlet hermits. i am not a big fan of hermits. i feel they are to aggressive towards snails even tho people say put plenty of empty shells in for the hermits. it doesnt matter they will still go after the snails.
when i bought my cleaner package i built my own. there is a site where you can build your cleaner crew instead of buying them pre built ones.
for my cleaner crew i got: astrea snails, cerith snails, nassarius snails, turbo snails, serpent starfish