That's kind of obvious, who would hoard their resources if they knew the game is about to end, might as well spend it all on some fun and XP.
It would never happen if people felt they were in any sort of danger of being conquered, e.g. at any other point of the game that isn't "the end". Nothing matters now.
Strategus v4 should be faster and with less troops in a battle, so hopefully more battles, less hoarding, more fun.
I personally cannot wait for there to be no ******* AI faction...