It shouldn't make any difference (at least not in UK). Sleeves up or down for everybody. Especially on a parade, doubly so with a senior officer on parade.
Why has the ACM got a Navy bird for a lackey?
As for why not in No1s, well it apparently saves dicking the blokes around. Also easier to wash the beer out of, as no doubt there would have been an enormous piss-up directly after the parade.