If I can take it down with a hold-out pistol and one net hit, then it's not heavily armored. As it is, a holdout pistol is all you need to take down every drone except the Steel Lynx and the FB-Bumblebee.
Now, granted, your probably shouldn't be in hold-out pistol range with any drone, but even at range, almost all drones will explode in a shower of twisted metal from a single hit by most combat-grade arms. The only exceptions are the Steel Lynx and the FB-Bumblebee and they'll be downed super quickly.
