In my opinion, all building buttons locations need to be improved by bringing them together to a single buttons scheme, just to bring clarity and convenience. I offer few variants:
Arranged to single scheme: all buttons placed in accordance to current human buttons scheme. Other variants are possible, but this has minimum changes. Hunter’s Hall button may be shifted to the left - more usual location and no empty slot between buttons, but the scheme won’t be entirely single for all races.
Alternative single scheme (is what I prefer the most): all buttons are orderly, empty slot turns up only in the 4th column, though it may be a little bit unusual, players will get used, not many changes here. Hunter’s Hall button may be shifted up, but that’s not recommended - not so usual location anyway and the scheme won’t be entirely single for all races.
At least what should be done with current state is improving of Night Elves building buttons locations: Ancient of Wind move to empty slot, Chimaera Roost and Ancient of Wonders shift to the left. I see no reasons why Night Elves buttons scheme should not correspond to the Orcish (in current state).