In Assassin’s Creed: Revelations for the PC, PS3, and Xbox 360, there are several skills that you can unlock in the game for your hirelings by completing certain challenges in challenge mode.
Here are the skills you can unlock, and which challenges you need to complete to unlock them.
Hired Mercenaries Stop Beggars – Complete the Set 2 Mercenary Challenges
Hired Romanies Poison Guards – Complete the Set 2 Romani Challenges
Hired Thieves Pickpocket – Complete the Set 2 Thief Challenges