I would make sure that he shoots at targets from a stand if he will be hunting off the ground and make sure his shooting form is good. I do not see why he can't go out and be successful as long as he has practiced.
I shot my first deer with a bow less than a month after getting my first bow and it was my second day on stand. I knew the deer was 15 yards so I set the pin on it right behind the shoulder where I had practiced and double lunged it, only had to walk 50 yards to get it. I have also seen people that have hunted for years get psyched out and miss deer even though they are good shots, so it all comes down to mental preperation in my eyes.