New Collective Noun

Since it's a hobby among Englishy-type teachers to develop or to collect collective nouns, I thought I'd add mine to the electronic pot.

You have a herd of cattle and a herd of horses (though that didn't sound quite right), but (thank you, James Lipton, for your Exaltation of Larks, a lovely book of collective nouns), you have a string of ponies. I've also heard of a pack of wild horses and a stud of mares.

But what would you call a group of mustangs?

Easy! A sally of mustangs!

ds