Building a bridge across a river, a bridge spanning more than five hundred meters, was not an overnight feat, even with the substantial assistance of magic.
Even if it were built, given the sheer size of the Conqueror Army, crossing the river would not be a simple matter, and action was not only being taken by us, but by Dark Castle as well.
They, like us, had clearly fallen victim to the Conqueror Army's deceit, deploying their main forces toward the Far Sea Marsh.
However, upon further consideration, they also had a scattered deployment of tributary forces in other areas, which should be able to cause some obstruction to the Conqueror Army.
Not only the Lizard Queen was disrupted by this move of the Conqueror Army, but the Ghost Witches of the Far Sea Marsh were caught off guard as well.
After all, the river crossing chosen by the Conqueror Army was closer to them, just a few steps out of the marsh and they would be upon us.