Apparently Bartok himself orchestrated the Roumanian Dances about which I was complaining recently.
Curious to explore the issue further, I checked on Wikipedia where there is a link to a recording of three of the dances by the Adelphi Chamber Orchestra (unknown to me). Listening to their sound I realized that they don't sound like any ensemble I have ever heard, nor would they probably be given the time of day were they to audition for a gig in NY in 2013. They are clearly playing with sounds in mind with which we are totally unfamiliar, and with a kind of manic energy that simply does not get conveyed in printed music.
So the orchestration is inseparable from the orchestra doing the playing. Had that been the version to which I was initially exposed things might have been altogether different. Who knows?