Is this true for English?

Nah, that's just what I'm going with. Sounds plausible enough, doesn't it? ;)

As far as I remember collective nouns are based on an old book (15th or 16th century) and there are some funny ones in there. I'll look it up and report later.

Edit: "The Book of Hawking, Hunting and Blasing of Arms" by Julia Berners published in England in 1486. It includes 165 collective nouns for groups of people and animals. I suppose the good gal was bored out of her mind and everyone just ran with it to humor her. And today we have have masterpieces like a "conspiracy of lemurs", "tower of giraffes", and "destruction of wild cats" (all real I swear).