you and fellow squaddie GHI
What?

Never been in a squad with GHI. Would be happy enough though if it were so.
A1+++++!Would voolch with again! +++++++1A

I like the arena changes too.
Mindy is difficult to reset because the "west" country has a narrow front. I only recall seeing the west country reset twice under the old rules. 40% is a huge ask whilst defending a long open front simultaneously. You're basically right, the west country holds an advantage in that it has little threat to defend against. It has the greatest chance of resetting. The problem for them is that if they roll forward north they get only a few bases forward and they hit the uncapturable area. If they go south they strike the same deal. In both cases they open up a wide flank which is easily porked and probed.
Make it about 30% and it is just attainable with effort.
The simple fact is that is this way because HTC currently choose to make it this way. I guess they must like it this way because they have shown not the slightest inclination to experiment with, adjust, or publicly review it for quite some time that I am aware of. That being so, get used to fighting on the same map for weeks, if not months, until a server crash or some other miracle occurs.
Of course they could fix it tomorrow. They've made good moves recently. They might even bin the "new" strat system. Who knows what lurks in the hearts of men?