User blog comment:Geomax/Space Marines vs Forerunner Warrior-Servants Rematch/@comment-5138827-20130105022920/@comment-1683193-20130106063207

http://forums.spacebattles.com/threads/culture-gelsuit-vs-didact.240614/ Bunch of info on Forerunner infantry weapons here. Space Marines should win this though.
 * Each Forerunner has an AI built into their combat skin.
 * They didn't dismantle their whole military, they dismantled some of it after building the Halo array as they considered it to render a conventional army obsolete, but they still had a large normal military force remaining.