Putting Giggs' qualifications aside, it seems unwise to me appoint to the blue eye boy of a previous regime and one whom I think hasn't actually shied away from seeking the managerial post itself. Is Giggs someone whose loyalty Van Gaal can trust - someone whom he could consult and discuss sensitive issues with, e.g. issues pertaining to specific players and the club? I'm not sure. With Giggs' ambition and relationship with the veteran players and Ferguson, I'm certain it won't be an easy relationship.
By accepting this arrangement, I think Van Gaal has come out looking a bit desperate in wanting the job. I hope it all falls apart. Having a disruptive Van Persie as his own blue eye boy in the dressing room is definitely going to help in that process. I hope.