Well, if you think so then really there is no point in continuing this. If a guy who has managed 4 matches isn't more risky than some of the best managers of all time, then what is the point on discussing this?
If you really believe this, then 'deluded' is a weak word to describe you (no offense there). I can understand people who want Giggs for some bizarre reasons (well, probably I can't understand them entirely) but saying that the risk with Giggs is not much (if at all) greater than other candidates it is an insane opinion.
"Best managers of all time"? I think I can throw your "deluded" comment right back at you there.
Guardiola took over a Barca team that already featured some of the best players in the world and one of the GOAT, in a fairly non-competitive league. He took that team up a level, but realistically I dont think anyone could call Barcelona a hard job when he took over. He enjoyed great success, and then burned out (a concern when thinking about the intensity of the PL), before joining Bayern - another great side, second only to Barca themselves in Europe. Again, not a hard job if we are being honest.
Guardiola has not had to build a team, he has not had to transition a a team or plan for the long term. His managerial record so far is purely one of joining a highly successful team, and continuing that success. He is largely unproven in pretty much all other areas, and there is the concern about him "burning out".
Ancelotti? Most of his success in recent years has come in clubs where he has been very much a short term appointment, and purely been required to deliver instant success while being given almost a blank chequebook. He hasnt lasted more than 3 years at a single club since 2009 (I believe).
Mourinho is much the same in that since Porto, his only jobs have been short term positions with a practically unlimited budget.
If anything, Klopp is the one who has a slightly different/better track record of taking a team and building something over several years, integrating new players, transitioning his teams, and not simply joining a "top of the pile" club, but rather giving himself a challenge, much like he has done again now with Liverpool. To me, that speaks volumes about him compared with those listed above.
You may argue "But Walrus, I dont care if we have short term appointments and spend lots of money, I just want trophies NOW at any cost!!!1" in which case I would suggest Man City or Chelsea would be a better club for you. I dont want to delve too deep into all the "losing our identity" stuff here, its more simply to illustrate that none of these so-called "best of all time" managers have really been tested recently, or sought out a challenge themselves, or handled any sort of long term approach. Hell, Mourinho is suffering his classic third season syndrome currently with Chelsea and looks like a fish out of water when (finally) faced with a bit of adversity, and generally when leaving clubs he leaves a big old mess for the next guy to have to clean up. Is that someone I want at United? Not really.
As I have said from the start - every appointment is a risk. The only person who is truly qualified for the United job is Ferguson, and even he would be a risk (outdated methods blah blah blah). Failing that, the next best person for me might as well be the one who has already been in the club, seen successful managers first hand and how they approached the job, and the various situations that came with it. A person who is being groomed for the position as we speak by a manager who is very serious about philosophy and structure, and who has stated that they are building a team for the next manager. If Giggs shows himself to not be up to the task, then he will be sacked, just like anyone else would be.