PC: Spur of the Heavens doesn't work right when combined with Charge

I have the following creatures in my party:
Unicorn Thundercracker
Fearsome Gargantuan

At the start of battle, all of my creatures attack three times (as expected), and Spur of the Heavens triggers on some of those attacks (as expected). However, if an enemy creature has more speed than any of mine (i.e. starts at the top of the queue), Spur of the Heavens places my creatures SECOND in the queue. Expected behavior would place my creatures at the top of the queue.