Does anyone spend more than 50% of their time hiring, firing, and disciplining?
Especially if hiring is done by the Human Relations Department, and firing/discipline is done by the operations manager/supervisor, then I doubt anyone spends any where near 50% of their time on these tasks.
But let's say a specific individual does all three tasks and has ten people working under him. Let's say it takes a full week to hire or fire someone. If such an individual hired a person every other week, and later fired a person every other week, he would have hired and fired his entire workforce in 40 weeks. He'd have to squeeze in over six weeks of progressive discipline somewhere to be over 50% for the year. And remember he's entitled to sick days, holidays, personal days, and several weeks vacation. Not to mention doing his other work.