When they finally set out, a day had already passed.
It took the fourth and eighth army an entire day to get all their supplies ready, which Lin Fan was let down about. However, he didn't blame them since this was already them moving fast.
If possible, they would have wanted to prepare for at least three days before heading out to ensure that all of their supplies were intact.
But at Lin Fan's insistence, they shortened it to a single day to get everything. The other supplies would be brought to them from supply depots around the battlefield, which would still give them the same level of supplies.
It was just that there was the chance that those supplies would be delayed or attacked for various reasons that made it much riskier.
Still, this was Lin Fan's insistence, so they had no choice.