The Whitespikes aren't exactly an intelligent race. They are feral, have no weapons, attack upon instinct rather than sadism, and appear to operate under a Hive Mind. All that, yet they came from a crashed spaceship. Surely they couldn’t have built that on their own given their behavior, so some more intelligent aliens must've sent them. It's possible that either the aliens intentionally sent the Whitespikes there in order to wipe out the human race so they could claim the planet for themselves, or it landed there by accident.
The people sent from the past to the future were not meant to win the war against the Whitespikes but were sent there to keep the Whitespikes distracted and occupied with “fresh meat”.
The future forces know that their only hope against the Whitespikes is to finish the toxin that is being researched and successfully deploy it. The people from the past who are drafted to fight the war in the future are being sent there as bait to keep the Whitespikes occupied and hopefully away from the research facility as well as away from Deep Swell 9. This would explain why those drafted were given rudimentary training and weapons that were barely effective. They were not meant to win, only to be a diversion. Once they run out of people to send to the future, the Whitespikes easily swarm the research facility and subsequently the Deep Swell 9.
