Edu's BBQ has a good in depth feature about Olabe out at the moment. It's a pretty skewed read (the blogger is a part time Sociedad anorak) but interesting.
What I took from it was that Olabe would be an alignment hire not an impact hire. He'd be coming from a football culture that's already informed the processes we have, and a club we already have close ties to. No surprises, and no challenges to Arteta's power base.
The other aspect is that Olabe has a very strong sales record at Sociedad, which is of course a selling club compared to what we are now ... but that's a set of skills we're really going to need.