I would triple those numbers (except maybe the cleaner shrimp, that'd be very expensive). Be careful with the cowrie unless you don't have a reef.
For approximate numbers in my 90g I have:
35 scarlet hermits
15 zebra hermits
25 blue leg hermits
15 cortez red leg hermits
10 mexican turbo snails
10 turbo snails
20 hawaiian nassarius
20 nassarius
20 cerith snails
10 of another small snail I can't remember the name
30 margarita snails
3 starfish in the brittle family
3 starfish in the linckia family
3 seacucumbers
1 blood fire shrimp
4 peppermint shrimp
1 fighting conch (2")
This has been an excellent crew, sometimes so efficient it completely consumes an animal still under guarantee before I can remove it. It is a mature and full reef tank so, no, it doesn't look like the tank is crawling with critters, they all blend in and hide very well.