OK, for all the people who don't understand why the other Halo games didn't have the AA's story wise is because the Spartans in Reach are Spartan 3's, a mass produced at the cost of efficiency type deal where they were individually weaker that S-2's but there were far more of them. They were made for suicide missions and given specific, lower grade armor that had slots for these upgrades that were meant to try and make up for the sheer loss of power at not having Mjonlnir Armor(The S-3's used the Semi-Powered-Infiltrator suits (SPI armor)) The S-3's were the only Spartans given these AA's, and all of it would have been deployed with them, or left on Onyx, Their base of training and possibly the site of the next game, and both ways the Tech was lost and never distributed to the S-2's. That's why we don't have the AA's in the other games. The Equipment in H3 looked mostly Covenant with the exception of the Human made Mine, which story wise would mainly appear in major Human defensive positions and planned expeditionary units.