yep, obviously I don't wanna know all the details, but there should be at least very good hints on how the engine works. If you don't have any idea of how it works what can you do? just put the player it seems to work best, there's no tactic (because you have no idea how and on what choosing another player will change the match).
An example: this week I played with a team with very good center. I decided to put my best defending center to defend him but I took another very good center to the position of PF. I really don't know if this is simply stupid and useless or a good tactic. And the dramatic thing is that noone can know (only try to guess)
You seem to overreact a bit. Have you read the "game engine" section in the Rules? It seems a good starting point to me.
Many thinks are quite intuitive, while many others you will have to learn with experience.
To answer your question. If you play man-to-man defense it is always 1vs1 play from players in the same position (C vs C, PF vs PF...). If you chose a zone defense, there will be a contribution from players in the same zone, like in reality.
But be careful. if you played 2-3 defense and your C is your best defender... you get a boost for defending the painted area with 3 players, but your C will help PF and SF more than they help him. So I guess that zone defense is better suited to help your weak spot than to reinforce your best position.