a guy with 10,000 hours short-haul is vastly more experienced in real
terms than 10,000 long haul hours.
A bit of flawed logic there, the long haul pilot will have worldwide weather and ATC conditions experience that the short haul pilot may not have. The flying experience is relative to the job on offer, if you are a short haul airline then the short haul experienced pilot is the favourite, if you are running a long haul airline etc. etc.
Now, if you want an interesting argument regarding the relevance of hours flown try convincing the Chief Pilot of a jet airline that your hours as a helicopter pilot, hands and feet on at all times, always fairly close to the ground, a rotor speed of .73Mach is at least as relevant as the long haul F/O's hours when he is PNF on the sector, say, UK to LAX, with the Capt. doing the flying and an FE sat behind on the panel!! Maybe today, but not a few years back.