they're definitely more drunk than you think
The other thing you need to remember is that they most likely only use their slings this one time of the year.
Take the balearic slingers - the good ones are very good and practice regularly.
But many of the slingers taking part in the competitions, don;'t really practice between competitions, are not good slingers and do it as much for the camraderie and social aspects as for the slinging.
And yes - booze is also drunk
I got quite tipsy at one comp last year. And still - with one hit - managed to beat quite a lot of the locals.
Hell pep ribasribas - the head of the federation, has not used a sling in living memory
My main goal this year is to get pep up to the line with a sling in his hand and a rock !
So there will be good peruvian slingers and they most likely will not be trying to kill anyone.