LOL with this analogy. Do I think I would have won a 3pt contest if I continued practicing??? Well, who is my competition? You see, we are not talking apples to oranges here. If I had the skill set to begin with (EG was drafted 7th) and I continued to work hard and practice, then yes... it would be reasonable to believe in myself to win such competition.
You kept stating that you can think of many 4year players who's shot didn't improve. Well, maybe they were not know as shooters to begin with. Maybe their scouting report was, "not a good shooter."
BTW, here was EG's draft scouting report I bolded the part about his shooting:
A rock-solid and incredibly explosive combo guard Tremendously aggressive, and relentless when going to the hoop Constantly looks to attack and use his body to out-muscle weaker defenders at his position Is not afraid of going at bigger help defenders and drawing contact Great leaping ability and outstanding body-control allow him to finish effectively around the hoop An assassin off the dribble, where a quick first step and combination of hesitation moves allow him get by people at will His remarkable speed and change of pace are best seen in the open court as he can be a 1-man fastbreak going around defenders with ease Possesses an extra gear that he displays at times, especially when turning the corner in the halfcourt Possesses a smooth jumpshot, which he is able to hit well beyond the NBA 3 He has a very quick and smooth release, great elevation as well as nice arc on his shot Has shown the ability to play with his back to the basket from the midpost, where he is able to utilize his terrific body strength and finishing ability to abuse smaller players Defensively, he has the potential to be great simply because of his physical tools (good length, nice lateral foot-speed and strength), combine that with his desire and decent understanding of team concepts, and he is already well ahead of the curve