Do you need your hair cut? More pressingly, is your leg hemmoraging toxic ichor and a malign curse creeping up the offending limb? Then drop by a barber-surgeon's office and get both done at once.
A barber-surgeon knows his/her/its way around a pair of scissors, hense why they are both pressed into the services of beautician and Doctor. While the very best barber-surgeons also know Life magic in theory. However no self-respecting Life Sorcerer/Elemenstor/Mage is also a barber-surgeon.
Generally speaking, you can trust your barber-surgeon about as far up as his main shaving/surgery implement is still sharp and/or clean.
They make amazing and subtle Warriors if you don't tell your enemies that the friendly healers you're sending over there are, in fact, barber-surgeons.