Border collie dogs doing intermidate agility. Only 4 dogs in group so very little time between runsof a short ?

course came wearing dog coats.. both long haired. in between each 2 min run on went the rug . There are greyhounds and the tiniest pooches go and have no need of a rug... doesnt it seem a little crazy to keep what was originally bred as a working sheep dog wrapped up in a coat? This was before the frosts came although it was chilly.