The poster above me gets it. Instead of removing the requirements, involve the other three more. Heck what about giving out XP for the crafts if you have non-max crafters involved. Make the other three folks useful instead of just 'one to work, three to supervise'.

What if different crafters could proc different bonuses? Or, if it really is a case of being unable to find folks, you could charge 'craft mammots' like buff wheels to use in a pinch?