I think Levy has gone for a cheap and relatively safe option. None of his targets are available as of yet. I don't get the impression Levy expects much from Ryan, but I think he expects him to mend some of the psychological and tactical damage caused by Jose, which is becoming more and more apparent.I know he's rapidly becoming more and more of a caricature of himself but I've championed Harry Redknapp since march. Simply because of his ability to put an arm around the likes of bale, Dele etc. I just can't see the point of mason. He's too young and we all know it. If Jose couldn't control Ndombele do we honestly think Mason will. It's just all wrong. I honestly think top 4 was there for the taking if we'd sacked Jose a fortnight earlier.
I don't know who else there was to pick for the interim role internally. It may have been Levy's only option. Obviously, Jose's team had to go and I wouldn't trust Sacramento to boil an egg let alone manage people.
As for externally, again not sure who is available/appropriate. Redknapp may be expensive or he not want to do it at all or for two months.