well, walk in's go in rotation, first in first tattooing etc... if the client wants something that you feel that your guy is not up to speed on that style, you should take him in the back and have a heart to heart, ask him, "you think your ready to tackle that tattoo?", and as a owner you got to be tuff love, it sucks to do whats right and fuckers bounce out on you because they think they deserve better treatment.
I have been around for 20 years, and a lot of owners are letting fuckers tattoo before they are ready, it is just bad business, period.
have him draw and shade out some jap and vintage tattoo art, at lest see if he understands what he is getting in to.
later skater