Mahon being number 1 is just a snapshot. As soon as ALD has lost some of her loser-systems things will change again.
Balancing is not done against standings, but against mechanics.
Some favoritism towards the Empire is listed in this thread:
https://forums.frontier.co.uk/showthread.php?t=158444
If you look at the list of community goals (community goals = income = powerplay power), you will see 4 / 4 community goals being about the Empire. Drawing players to the Empire.
The thing is that the favoritism is getting on our nerves.
Number of Alliance ships: 0 (Empire: 3).
Number of Alliance powers: 1 (Empire: 4).
Number of Alliance CGs... well, we had 2 around Alioth, 2 around the old worlds, one exploration goal and a bunch of terraforming cgs. Plus 2 player group cgs. That's about as much as every single Empire power.
Every Empire power has better bonusses than every other power.
And you can see it in the participation numbers. Every single of these favoritisms draws players to the powers. The CGs. The ships. The ranks. The bonusses. GalNet Coverage. You could even say: Who are the good looking powers? The Empire powers. All others are ugly, or strange at best (maybe apart from Winters, who looks okayish. EDIT: And apart from Torval, to be fair).
It needs to be pointed out once in a while. And it always continues.