"How on Earth would that work?!"

Well here's the idea folks:

This little bug would replace the pistol slot and give you a counter to all sapper; acting as a defensive drone. You can use it to repair buildings and destroy sappers without line of site.

The trade off? Marked for death when it is deployed or attacking (Spy or Sapper; not repairing).

The ammo would be metal and cost 100 to deploy. So par this with the rescue ranger and and engineer can be a mobile powerhouse.

Thoughts?