Scottish trad has an easier time with this since we have a long established tradition of sets of tunes in different tempo - "march, strathspey and reel" aka "MSR", "slow air, march, strathspey and reel" or (less commonly except in the competition scene) "hornpipe and jig". With clusters like that it makes sense to step up the instrumentation as things get louder and faster.

The 74th Fraser Highlanders pipe band are great at tune set arrangements, just using varying numbers of bagpipes and drums. In the folk band scene I don't think the Whistlebinkies have ever been equalled at that, though they were never the most high-energy group around.

Most ceilidh bands will change instrumentation sometimes when a new tune coincides with a new dance figure, to give the clearest possible cue to the dancers. They generally don't go in for random changes within a tune.