I'd like to see a Locust in Halo 5 honestly, it could totally work with some adjustments to how the mantis is.
The Locust would likely be a little slower than the Mantis. However, I'm sure this could be compensated with by offering the Locust a little extra endurance making it a little harder to kill as well. In terms of weapons for the platform, I'd suggest the possibility of a similar but enlarged variation of the covey sniper from Reach, a beam that would over-heat given that it was held down too long, but would also grow in power as the trigger was held(It would absolutely NOT function as the spartan laser does). Now the thing to this would be that just like the Mantis, the gun would have to reload, right? Well, top that I'd offer the solution of its' reloading mechanism be something similar to that of the covey's plasma repeater, where it would vent the weapon more so than reload it. However, if you were to simply hold the button down until the beam over-heated, it would take longer for the weapon to cool enough to return to a usable state (as it had indeed, over-heated and not simply been vented prior to said event).
As per the secondary armament, I'd suggest the possibility of it being a covey equivalent to the rocket pods: Fuel Rods. Now, a lot of folks seem to think that fuel rods aren't that great, but hear me out. Fuel rods, while they may not necessarily be a one hit kill capable weapon on vehicles (though it has happened) they still provide a wonderful amount of support for the statistics of the provided vehicle platform. The fuel rod is more than capable of propelling other vehicles away quite well, as well as providing a solid defense against incoming infantry. The launcher itself would likely function in a way quite similar to that of the Mantis rocket-launcher, but may have a slightly (and do I mean EVER so slightly) reload speed given its' slightly lower overall power/damage.
To be fair, the Locust would not be able to crouch (as it has non-segmented legs, see H.W.) such as how the Mantis can, so as opposed to the B button (or equivalent pc/whatever keybinding) crouching the Locust, it could slightly raise it, providing the main body of the station were actually set slightly lower in the legs with supports that may enable the main chassis to be raised making it move at an even slower rate in exchange for a slight height advantage (such as peering over a small hill etc, enabling it to possibly get a bead on an incoming vehicle, or even, a saving grace laze that may just do that last little amount of damage to drop a hog loaded with a flag/bomb carrier).
I think that just about covers the main thought, obviously there are things that can be argued about it and that's perfectly a-okay by me. A big thanks out to my buddy spartan_J03 who actually got me to jump on here and toss something in. He's a trooper lol.