By the way:
1) on 1280x720 resolution max party is 8 mercs and on 1024x768 - 10. As I see in code there checks both for width and height, but there need only for width.
2) there few problems with redraw on same resolution, for example after closing invntory on map screen it doesnt update ofscreen buffer and part of this menu is still visible.
3) never ideas for encreasing interface for wildscreen resolutions, as nowdays the most people have wildscreen monitors?

(I'm pretty satisfied with the current interface on wide screens though. IMHO, time & effort could be better put elsewhere like optimizing the scaler filters performance.)