Both Lebron James and Cristiano Ronaldo are top players at their sports, and known for their high athleticism. You wouldn't expect them to switch and still be performing at the level they do.
Heck, you wouldn't even expect them to be performing at a high capacity if you just switched positions inside their own team!.
As I said in other comments, I agree with the general premise of what you say. I also do, on the other hand, have some experience of the common workplace to know that sometimes, low performance is low commitment or carelessness. And both will very possibly transfer to other position. Again, previous performance is not a great indicator; I understand, however, that people might have to resort to it sometimes.
Irrelevant to the analogy. A striker cannot play in central defence, or vice versa. That's the point.
Sure they can. Perhaps not as well, but I bet a premier division striker will easily be able to play defense for a lower division team, and with a bit of experience could probably become really good. Hell I'm sure LeBron James could make a pretty decent soccer player if someone gave him some coaching and the right incentives.
Don't even need to get out of football to think of an example where this experiment has failed. Falcão is to this day considered one of the greatest players of indoor football. He tried to get into football by playing for São Paulo FC and stayed in the bench for most of the season, then went back to futsal.
Or if you want to go back to Basketball: Michael Jordan and his baseball career.
In any case, what I am trying to say is that you seem too quick to pin the lack of performance in the "common workplace" on the individual, when there are so many other parts on the system that can and should be analyzed. What the others and I are saying is "no, we can't say that poor performance 'will very possible transfer to the other position". Especially if you have access to the people that worked with them and can have a deeper look at the context, it makes no sense to be looking at past performance to judge potential.
Sorry, but no, not at all. I explicitly said "sometimes": "sometimes, low performance is low commitment or carelessness". My message since the beginning has been that, while not a great indicator, previous performance will at least have some correlation with future performance. Again, it's not great, but it's also not a random relationship.
I hope it goest without saying, you can and should try to have a deeper look at the context.