There's no use puff,dumb fool(seriously, aren't puffing just make themself bigger to scare enemy off?)
Yeah IRL that's pretty much why some animals do Puff or paralels for puffing, to some degree yukkuris do follow that logic but at some point (probably because of asshole wizard modification shenanigans) they started to assume Puff is some magical spell power capable of actually harming and insta kill their enemies.
Of course some yu's still remember puff is only good for scaring but way too many assume what I mentioned before, and chances are a great deal of this is because it's super effective against each other (at least in asserting dominance) so that just feeds their delusion.