Zeldor - saying that no matter how much you can stale, nobody will EVER arrive in time to take part in the middle of a battle, makes me ask so how armies intercept each others, or how they just MOVE from one territory to another (even 3, 4 provinces far if they are fast) in one month.
For the comment about your late game, well it is so realistic that it is self-explanatory to me. There were huge forces in your battle, balanced, none of them preponderant. Were they supposed to kill each other completely in one month if after 50 turns probably some unit didn't even come in contact to the enemy? probably not
You and your enemies tried to win of course, not trying to stale, but still it takes too much time to huge armies to completely annihilate each other - in the game as in real war. The biggest clashes of the 100 years war weren't resolved in just one month, or it would have been called the A Couple Of Months War