How many wrasse in 40 breeder?

[Bluesop7]

Just like the title says....how many wrasse would it be ok to keep in a 40 gallon breeder? I have a 20 gallon sump, probably 60 pounds of LR with 10 of it in the sump. The other fish I plan on keeping thus far are as follows (I dont have any fish yet):

Dartfish
Maroon Clown
A wrasse/s

I was thinking about a carpenters flasher wrasse and a red velvet fairy wrasse. Any thoughts?