Have you actually been in a shearing shed during shearing time? Doesn't sound like it.
Nice of you to be so concerned with the sheep's emotional well being, but that's the last thing on the minds of the guys doing the job. I suspect you would be horrified at the way the sheep are treated, but that's the side of farming they don't show on those nice BBC shows about farming.
BTW, the guys that shear big mobs know how to shear as many as possible in as short a time as possible- they are always in a "race", against time. Being in a contest would make little difference.
For the benefit of the OP, bringing in a few hundred/ thousand sheep would be problematic, given space and feed requirements, plus the animal luvvies would put so many restrictions on it for the "animal welfare" that most would not be interested in doing it.
Also, there wouldn't be much chance of any other than Kiwis or Aussies getting gold or silver. I'd have said Kiwis for sure, but the flock size has gone down by a few million in past years as wool is worthless.