Yes and no. My unscientific opinion is that the guarded blades are more for psychological effect.
"Yes" in that they can give one more confidence to try and might provide for some margin of error but I could not really see a difference when I was starting out, but my first 10-15 shaves were with a guarded blade so they may have prevented worse disasters, but I will never know.
"No" in the sense it does not prevent nicks or from you gouging the point into your face, so they are certainly not a license to use bad technique. Using almost no pressure on the cutting edge is the most important aspect of technique.
All that said, I think you have to nick/cut yourself to actually learn the boundaries of your face and the razor, that there are no short cuts
to learning.
