> Give it aerial capability, even if it's just enough to hop over a hedgehog or a smaller river, and the ability to defend itself while airborne, and the game becomes much more serious.

Again, the whole idea presented in this article is that it responds to people pushing on it. What you have just described is what a standard, existing aerial drone is capable of. There is already terrain-following tech that allows a drone to stay at a given height above the ground.