In Wind and Truth, why didn't they...
I'm re-reading wind and truth at the moment, and after the council of monarchs is discussing the loophole in the contract that hoid points out, I realized that the best move imo would be for all the monarchs of their respective kingdoms to name urithiru as their new capital.
Sure, logistically to do so in 8 days would be a tall order, especially for the azish I'm sure, but there'd be no more scrambling over which troops go where, because having all troops at urithiru would simultaneously defend all the kingdoms.
Plus, they could always revert it back after the showdown. And the cherry on top is that since the contract loophole works both ways, jasnah naming urithiru as the capital of alethkar would mean that after the contest, since they control the capital of alethkar, they control all the territories of that kingdom, including kolinar.
I'm not sure if I'm missing anything, this is only my second reread. But the thought popped into my head and it seemed like the best solution for everyone, even if it would be beauracratically hard to convince monarchs to name urithiru as their capital