Does he? Nobody had heard of him before last year and this absolutely smacks of flavour of the month, someone like Monchi has been doing it for years. Arguments about South American players are absolutely valid but come on, we are supposed to be dining at the top table now, which European players will even know Walsh?
Honestly, I don't think players care who the director of football is.
He's the guy that finds them and negotiates with their agents. They won't likely work with him day to day. If we pay them enough, they won't give a damn whether he's Steve Walsh or El Conquistador, the greatest fencing flamenco-dancing striker of all.
Monchi has not done it in England. He's as much, or more of a risk than Walsh. Which isn't to say he'd fail or Walsh will succeed. It's just to point out that nationality likely has nearly nothing to do with ones ability to scout talent, and experience in the league may actually be important, considering how many high profile failures have occurred with European stars moving to the Prem.
Monchi also has had the benefit of working in a big league at a biggish club, but not too big to take risks on unknown players. Real/Barca don't buy that type. Sevilla is a great destination for players that haven't proven themselves coming from places that UK law would cause work permit problems.
Not arguing he doesn't have talent. But it's a complete unknown how it would transfer (still would have liked to find out, like).