your vision is always there, your shotmaking isn't
Position play includes seeing patterns to be able to play position. That perception of patterns is always there once you master it, assuming you are in a condition fit to play. Some days even the greatest shot makers are a little bit off and they are only very good shot makers. Too, even great ones bobble when they keep having to come with great shots over and over.
With good position play angles do much or all of the work getting to the next shot that people with weaker position skills rely on spin to take care of. Less side spin makes shots easier. Shooting easier shots most of the time the position player may have to shoot a great shot only a few times a set while a great shot maker with poor position play is much more reliant on having to make the big play over and over.
Great shots, big plays, hero moves passing on a racetrack, they all carry a large element of risk. Succeed and you are a hero, fail and you often hand victory to your opponent.
I have to admit that I have never seen a great position player that wasn't a very good shot maker or a great shot maker that wasn't a pretty good position player. To be very very good at either one requires putting in the hours on the table. Putting the hours in on the table means you are likely to be pretty good at both.
In the long grind I would always bet the stronger position player over the great shot maker with both just slightly behind in the other skill. The stronger position player is better able to control the table. When you find a great shot maker and great position player you get The Magician.
Hu