Where’s our Wolverine, Cobra, Grizzly, or Locust?
Wolverines would be great to shut down pesky Banshee-spammers, while Cobras could be the ultimate DPS vehicle for killing bosses (but lacking the splash capability of Scorpions and Wraiths). Locusts could add a nice anti-vehicle option for Covie-lovers, providing you with a powerful direct-fire beam weapon that can melt a Scorpion pretty quickly if left unchecked, but would be weak to close-up attack. (Yes, the Locust loses easily to Scorpions in Halo Wars, but just imagine that the current Locust is upgraded to a tank-destroyer role.)
And then there’s Forge’s pet project, the Grizzly tank. Sure, double-barrelled tanks are impractical, but this is sci-fi, and it’d be fun as heck to have two cannons firing instead of just one. To make it balanced, I’d have the Grizzly be a tank that works better against infantry due to larger explosive payload, but worse against other vehicles due to lack of penetration power, so a Scorpion would beat it in 1v1 combat.
Serious, 343 isn’t fully representing the UNSC’s arsenal if they don’t include these vehicles.