I think that in high points games as more and more points are spent the attacker gains a bigger and bigger advantage. So I use these formulas to decrease the overall points allocated to the attacker as the points increase.
Assault; y=.000006x^2+(5/12)x Advance; y=.000006x^2+(7/12)x
For low points games these curves give ratios of 2.4:1 for assaults and 1.7:1 for advance, which is my preference.
For a game with 6000 assault points the curve has given the defender 2716 points to defend with compared to the 2500 for a straight line of 2.4:1
For a game with 6000 advance points the curve has given the delayer 3716 points to defend with compared to the 3530 for a straight line of 1.7:1
With my curves in an advance game of 65000 points the delayer will get 63266 points. In an assault game of 65000 points the defender will get 38236 points.
If you like this idea I can calculate the curves that fit your game ratios at the start and then arrive at the discounted value you choose at 65000 points.