you're thinking about it the wrong way. the effectiveness of each level of the zone (either the 2 or the 3) is determined by the average ratings of the players on the court. so to simplify it, if you have DEF of 50 and 90, you effectively have a 70 for the two. your PG isn't assigned to one side of the court or the other. the only thing that I think may happen is in the 2-3, the C is going to have the most shot blocking opportunities. i've moved guys between the 4 and 5 in my zone and seem to get more blocks in the 5. that's anecdotal so it may not be the most accurate. Look at average speed, defense, shot blocking, etc., for each level to get a sense of how effective your team might be on D. set the +/- to adjust balance between defending the 3 pt line and getting rebounds.