Well one way to check the math will be to use some equity calculator and evaluate your AX hand against (X-1) opponents with random hands.
I used online calculator at http://propokertools.com/
This is what I got:
A2 against 1 player : you: 55.5% equity; opp : 44.5%
A3 against 2 players: you: 37% equity; opps: 31,5%
A4 against 3 players: you: 28% equity; opps: 24%
A5 against 4 players: you: 23% equity; opps: 19%
A6 against 5 players: you: 18.4% equity; opps: 16.3%
So, rule in question indeed gives you some edge over your opponents. But basically it's a true coin flip with only few percents handicap for you. And these few percents rapidly shrink with the increase of number of players in front of you.
Just for fun I tried same approach but for rule AX when there are (X-2) players in front of you:
A3 vs 1 opp : your equity 56.5%
A4 vs 2 opps: your equity 38%
A5 vs 3 opps: your equity 29%
A6 vs 4 opps: your equity 22.5% (yeah, A5 is better then A6, because of Wheel)
A7 vs 5 opps: your equity 19.4%
So, improved rule gave you only 1% equity increase (and for A6 its even worse).
Hope this answer makes mathematical side of the problem clearer. Otherwise I should agree with others, that usually you don't want rely on a little-bit-better-than-coin-flip solutions, usually you want to rely on skill. Still with 10bb skill may show itself in selecting a situation when your coin-flip is at least few percents handicapped towards your side.