There are several reasons for that board size:
- Many pieces can move very fast over the board, making it possible to actually play tactically, not just strategically (building walls with the adventurers and such, though that is possible too)
- An octarch needs space to actually be able to run away, once his temple is taken over
- With that setup all fields on a players side are covered, giving little security against very soon and not well thought out attacks
- In a few moves (taking the hero on the starting position as example) you come to a good position at the rim of the opponents side, without entering yet
I don't think the board size itself is a problem. If people actually complain about the start being too slow, I rather change the starting positions and/or movement rules of the units than the board size. Doesn't mean that I ultimately will never consider changing the size, of course. With good reasons and some actual examples I am convinceable
It's also the question how the fields being hexagonal are affecting the gameplay, considering the higher freedom for each piece.
Just a random sidenote: I calculated a bit after those concerns regarding the board size
european chess: 64 fields, 16 pieces per player = 32 pieces -> 32:32 fields = 1:1 (covered:free)
chinese chess: 90 line crossings (you play on the lines, not the fields), 16 pieces per player = 32 pieces -> 32:58 =1:1,8125 =(about) 1:2
octarchs chess: 144 fields, 18 pieces per player = 36 pieces -> 36:108 fields = 1:3
PS (offtopic): I also tried to calculate with the help of a formula how many usable line crossings (fields where you could move to, if one played on the lines instead) this board has and i failed horribly >.>
Edit: I found a formula, but not sure if it is right. The first attempt was by counting the edges of the fields and deriving the number of crossings by that. Second now:
2 x Sigma [from 1 to 12]=(2n+1)
