Your introducing a serious amount of characters?
When having such a subtle (hafif) extrusion, I usually preffer to handle it with a bump/displacement map instead.
Usually because it gives me more independence from the shapes the polygons would allow me. And secondly that such a mustache may interfere to my mouths topology shall I want to have him have a change in expression.
But I see that in your state It is a diffrent matter as you are depicting pawns. It does add to it.
Are you going to do something about the center line running along the face?
Lol… no I am no master. Thank you very much. But I guess there are many more that would be more fitting to such a title 
As for the school… If you do the sales… I can try and do all the teaching :deal: I am so so with teaching… but I am a very bad business man :sad:
(Hocam kusura bakma hep ingilizce… senin nasil olsa cok iyi dilin, ve ayip oluyor oteki gezenlere. Anlamiyorlar ya)