ANY HELP WITH SCENARIO DESIGN PLEASE!

[Glint]

I'm constructing a scenario design and wonder if someone could advise me over Victory conditions scores?
It involves equal 6000pt forces each with 1500pts of objective points held, each side at the beginning.
It's a hypothetical scenario and the intention is for either force to grab the other sides objectives and destroy as much of the enemy forces as possible.
At commencement, obviously the victory score should be in the centre of the draw range. I tallied with acceptable losses of a ratio of 20% to 30%. Could anyone advise a realistic spread of Major/Minor victories/defeats ?
Your advices would be most appreciated.
regards
Peter