Targeting systems

Drones

bigger heavier equipment capabilities

Bigger Drones

nimbleness over odd terrain

Drones

Under no circumstances is walking better than flying, tactically. Once you introduce airborne combat, a mech loses all tactical benefit. Tanks/mobile artillery? Sure, that you can justify, mostly because it's low profile and easier to hide if necessary. In almost every other circumstance, if you can have an airborne gunship you want an airborne gunship, and you don't even have to alter the laws of physics to make them work.

The only way you could make the case for mechs is if whatever magic Clarke-Tech you were imagining for moving them was astronomically more efficient than flying for approximately the same tonnage, and you were desperate to conserve as much energy as possible, to the point where flight just isn't an option, and even then, the most efficient machine would look something like a gigantic beetle.