What kind consistency are we talking about here? I'm not talking about spending 1-3 hours shooting straight ins until they make 10 in a row or even 30 minutes, I mean within a couple of tries. And just to make sure we're on the same page, by long shots I mean OB in the centre of the table, CB 3-5 inches from the end rail (so comfortable cueing). My point is simply perfect stroke and alignement makes the aiming process considerably easier.
Under normal circumstances a player on his way to achieving this would have learned to aim at some point. Otherwise what have they been practicing?
But to answer your hypothetical I would suspect a player who has never attempted a cut shot but can make 10 out of 10 straight ins, would probably manage 2-4 out of 10 half ball hits (maybe more or less depending on the distance). A raw beginner with no playing experience will manage 0-2 I think.
I can completely understand the spot shot guy. I'm guessing he doesn't aim where you or I do for spot shots, because he is probably compensating for a poor delivery or alignement (but can do both consistently the same way).
Well then I agree with you that a player who has learned to aim and can deliver consistently through proper fundamentals doesn't really need to change to any thing other than what they are using. We aren't talking about that player here.
We are talking about the player who has trouble on certain shots, is inconsistent but has decent fundamentals. The guy who gets down on the shot with the feeling that he is perfect and still misses.
It's been proven adequately I think that a cue stick deflects variably depending on how it's oriented in relation to the shot. Thus before the introduction of truly radially consistent cues it was certainly true that players could miss shots that they were otherwise perfectly lined up on due to the variable deflection of their cue. But most people did not know this. Some did. Jimmy Reid marked his cue so that it was in the same direction each time he addressed the ball.
So I firmly believe that the same thing applies to aiming in general. You can take a person who has perfect fundamentals, straight stroke, great stance, perfect follow through, etc... and that person can still miss balls because they aren't aligning themselves properly from shot to shot. Why NOT? Maybe they can't always imagine the ghost ball just right - they think that they do. Maybe they see the balls one way when facing a shot to the right and the other way for a shot to the left.
And yes, they can overcome a lot of this through repetition. The idea would be that IF they see shots to left differently that after shooting a couple hundred balls they would have figured out the adjustment. And I bet most people do it this way as it's the only way they have.
This is where some systems come in. Not only CTE, but Joe Tucker's numbers, Contact Point Lines, Light Reflection etc.... For some people these things work to help them find the right line no matter if the shot is to the right or to the left.
I know a guy - we will call him Goofy George - who specializes in going to bars and poolrooms and playing with the worst styles you can imagine. He has a whole traveling chest of things he can do to make you think he couldn't drop a ball and hit the floor much less make a ball in the hole. George has the art down so well that players fight each other for the right to spot him balls, games, odds on the money etc. He has a secret though, he has a method to aim that allows him to line up perfect every time. So when he wants to make a shot he can step into it dead perfect and if he wants to miss he simply steps in slightly off. The whole time he keeps up this "act" and by doing so he "lucks" balls in, he misses widely and leaves his opponent tough, he misses hangers and makes that long tough cut - all the while his opponent is *****ing about how lucky he is.
Goofy George is proof positive that you don't have to be dead perfect on your set up and your pre-shot routine as long as you can get down and fire on the right aiming line.
Does Goofy George win heads-up matches with great players. Sometimes yes and sometimes no. When he plays those players he plays straight up without all the theatrics and of course he faces the same pressures as any other player getting heat put on him. If he is on the stall and manages to trap a good player then he wins easily. If he is playing a decent amateur or below then they usually have no chance.
Now I don't really approve of Goofy George's hustling tactics. He told me that playing pool for money is like robbing people without a gun. But what I learned from him is that if you have a reliable way to aim THEN everything else falls into place and you don't have to look like a textbook perfect player at the table.