Classic D&D ability score shifting thought

I have written about how I dropped intelligence from my Skylands classic D&D campaign. And about how I might like to replace it with quickness. And how the scores might be grouped into three related pairs.

One reason for pairing them is that at least one of my players thought that dexterity and quickness should be related. That it should be unusual for them to be very different. (While I argue that I myself am a example of them being fairly different. While I—at least in my youth—had decent dexterity, I have never been quick.) Anywho...what I want to talk about today is this idea:

All six scores are rolled separately. In each of the pairs (strength and constitution, dexterity and quickness, charisma and wisdom), the higher score my be lowered and the same number of points added to the lower score. But the lower score cannot be raised past the higher score.

e.g. I roll 10 for dexterity and 14 for quickness. I could raise dexterity to 11 by lowering quickness to 13. I could raise dexterity to 12 by lowering quickness to 12. But I couldn’t raise dexterity past 12.

Since I use the B/X modifiers, a smart player will consider the break points. e.g. If 17 was rolled for strength and 12 for constitution, it makes sense to lower the 17 to 16 because both have a +2 modifier while bumping the 12 to 13 goes from a +0 to a +1. I don’t think this is a bad thing.

On the other hand, I’m known to call for ability checks against the actual score, so—when that happens—the difference between a 17 and an 18 can be significant.