Hi,
I am trying to do something where if I have matching quantities of 2 SKUs then a fixed discount is applied.
i.e.
 
The discount should be £10.
1 of product of X, 1 of Product Y, £10 discount.
1 of product of X, 0 of Product Y, Discount not applied.
0 of product of X, 1 of Product Y, Discount not applied.
 
The problem is the following combination
 
1 of product of X, 2 of Product Y, £15 discount.
 
Below is how my rule is currently setup
 

 
Much Appreciated
 
Thank You