In my humble opinion the thing that tends to define natural talent in paintball (and in certain other things as well) tends to be situational awareness. That us the ability to keep track of the location and situation of as many members of both teams as possible all at the same time.
Its something that everyone does differently and is mostly dependant on the person involved, with different people having various abilities in different situations. Some people are naturally able to keep track of every person on the field and the information comes to mind instantly, while others struggle beyond keeping track of one or two players. Its also a case of keeping track of players regardless of outside distractions (something that often causes a player to get tunnel vision and focus too much on a single enemy player).
Its vital regardless of the position you play it allows you to corordinate actions well (both for yourself and your team mates), know where to lay down paint to have the most effect, and to know how far you can come out of a bunker at a certain time to look for that ellusive angle...
A lot of people speak about 'timing' as being one of the most important aspects of paintball and they would be right, its really obvious when someone makes a brilliant mugging move taking out players that just don't see them coming. Timing is mearly an extension though of situationaly awareness, as the true art to timing a run such as that, comes from knowing that all the guys who could shoot you out are looking the other way. Thats what situational awareness is all about. You see a player (such as Chris Lasoya) go off and mug three enemy players in quick sucsession, and its not because some devine being has come down and whispered in his ear that now is a good time to go, its because he has been watching the opposition and listoning to his team mates tell him what they are doing, and he is able to form a picture in his mind that enables him to run a path that is completely unseen by the opposition at that time. That picture is of course constantly changing and with possibly ten enemy players on the pitch it very rapidly becomes confusing and hard to follow for anyone without such natural talent in that area. It is also vital for players to be able to communicate information well as it allows players to keep track of players even if they can't see them, but one of their team mates can. The perfect ten man team being ten seperate entities each knowing all the information that the others know...
Now its not just some all encompassing talent that you either have or you haven't got, it can of course be improved by training (walking the field well allows you to see what each and every player can see from there bunker and thus make the picture clearer, experience allows you to predict any unseen moves and so on), but there is a limit to everyones cognative capacity in that area and those who are better at it tend to do better. Just as only a small percentage of people are natural say fighter pilots (where a different form of situational awareness is vital to track multiple aircraft) or submarine captains (where yet another form of situational awareness is required to navigate in three dimensions while considering natural surroundings and other (possibly hostile) submarines when you can't even see), likewise some people are naturals at keeping track during a game of paintball. So going back to the point regarding the Russian Legion, they have only a small pool of players to draw from so understandably they are much less likely to find people with great situational awareness in paintball and as such are of course at a disadvantage when compared to the American Teams who can draw on a huge pool of talent.
This is not of course the only thing that seperates the great from the not so great paintballers but its something very difficult to teach, and everyone does have there limits in this regard and as such is very important. The Russian Legion have shown what training can accomplish and if someone ever combines the large talent pool of the Americans with their training methods then they will take paintball to a whole new level.