I find it interesting that you would compare Banchero to Siakam. Siakam came into the league after his Junior season (6 months older than Murray) with almost no skills to speak of. He was athletic, could run the floor, rebound and hopefully defend. He was a poor ball handler, couldn't shoot and had shown zero vision as a passer.
Did you make the prediction at draft time that Siakam would wind up being a 20+ppg scorer that could shoot the 3 and show point forward skills or did you think he would be a hustle guy like the rest of us? I don't remember you making that prediction but if you did, then I'd be the first to give you props. I personally didn't think he would develop into what he's developed into and his development certainly is not the norm. I would venture to guess the amount of people that properly predicted Siakam's ceiling is less than .01%.
I've never said that it's impossible to develop a skill that has never been shown. I'm just saying it's improbable. I don't understand why you guys keep conflating the two over and over.
If you think that players can just develop whatever skill out of thin air, then why even scout? Just pick any player and develop them into whatever you want.
For every Siakam, there's a whole bunch of Skals and Bagleys. Picking the one guy who miraculously developed skills he never had and then projecting that rarity onto random prospects is a losing battle and defeats the entire purpose of scouting. There is an entire league of G League players that just can't develop those skills no matter how hard they try.
Scouting obviously isn't black and white but just trying to wish a skill into existence for a player because another player developed that skill is going to make you wrong much more often than it'll make you right. They've got to show something in order for you to be able to make a somewhat accurate prediction. Anything else is just a pure guess.