Make no apologies. Big wide open places can be boring unless you have defined groups, advanced planning, understanding of battlefield tactics, and proper toon selection to support such warfare.
With such an ecclectic group, a more "choke point" oriented format makes sense, and is easier to control as you stated. Maybe in the future with more defined guild structures and teams set up for such battles, things such as large open warfare can take place.
I understand the previously stated desires for proper flanking ability, freedom of movement, and other considerations, but hey man....we got to do some fighting. hehe. All in good time and with more planning by players, not just staff, it will all come to fruition.
Hooya.