Wellcome Etendar
I also dont write well in inglish, I write/read much better in spanish/portuguese, If you wish my squad page in Brazil is
www.gavca.com (I am also a mission builder

)
In fact is not a limitation, but the logic of the system: you set only one side to attack/defense and the program invert the symbols for defense/attack. To IL2 all area of attack is an area of defence, and vice-versa.
Saludos!