In my company's travel policy it is stated that we have to travel the full itinerary booked, and in case of a cancellation, it needs to be done via our corporate travel agent.
It happened to me in the past to show them that instead of buying 2x OTP-PRG flights with one night in PRG I could buy 2 separate tickets (OTP-PRG-OTP + PRG-OTP-PRG) for cheaper, and it took Hierarchy to convince TA that 600EUR < 1200 EUR