It's from the same people that brought you "chai tea latte" or "tea with milk tea milk"
But I'm actually ok with groupset. Sounds vaguely British.
EDIT: As a bit of a word nerd, I delved further. While Newspapers.com is by no means definitive, looks like "groupset" first started being used in the 1980s in, as I had guessed, the UK.
Here's an ad from the South Wales Evening Post, Fri, Oct 10, 1986
Macclesfield Express Thu, Mar 31, 1988
Birmingham Metronews Fri, Nov 24, 1989
Someone in Atlanta started using "groupset" in late 1987 - see the Bataglin
The Atlanta Journal Thu, Nov 12, 1987
Within Newspaper.com's print dataset, "groupset" as a term died at the turn of the century.
