I played around with optimizing this strategy, coming up with a potent-yet-cheap suicide squad.
The basic unit is a 10 ton VTOL with a 100 fuel cell engine.
Suicide VTOL
Mass: 10 tons
Movement Type: VTOL
Power Plant: 100 Fuel Cell
Cruising Speed: 162 kph
Maximum Speed: 248.4 kph
Armor: Standard
Armament:
Manufacturer: Unknown
Primary Factory: Unknown
Communication System: Unknown
Targeting & Tracking System: Unknown
Introduction Year: 3145
Tech Rating/Availability: E/X-X-X-E
Cost: 308,889 C-bills
Type: Suicide VTOL
Technology Base: Inner Sphere (Experimental)
Movement Type: VTOL
Tonnage: 10
Battle Value: 67
Equipment Mass
Internal Structure 1
Engine 100 Fuel Cell 4
Cruising MP: 15
Flank MP: 23
Heat Sinks: 1 0
Control Equipment: 0.5
Lift Equipment: 1.0
Power Amplifier: 0.0
Armor Factor 16 1
Internal Armor
Structure Value
Front 1 6
R/L Side 1/1 3/3
Rear 1 2
Rotor 1 2
Weapons
and Ammo Location Tonnage
Booby Trap Body 1.0
Drone Operating System Body 1.5
The 1 ton of armor should be fine for dealing with the occasional stray AC/2 shot.
One difficulty with this strategy is that drones shut down within an ECM field. This can be countered with an ECM in ECCM mode.
Suicide VTOL ECM
Mass: 15 tons
Movement Type: VTOL
Power Plant: 115 Fuel Cell
Cruising Speed: 151.2 kph
Maximum Speed: 226.8 kph
Armor: Standard
Armament:
Manufacturer: Unknown
Primary Factory: Unknown
Communication System: Unknown
Targeting & Tracking System: Unknown
Introduction Year: 3145
Tech Rating/Availability: E/X-X-X-E
Cost: 750,750 C-bills
Type: Suicide VTOL
Technology Base: Inner Sphere (Experimental)
Movement Type: VTOL
Tonnage: 15
Battle Value: 146
Equipment Mass
Internal Structure 1.5
Engine 115 Fuel Cell 5
Cruising MP: 14
Flank MP: 21
Heat Sinks: 1 0
Control Equipment: 1.0
Lift Equipment: 1.5
Power Amplifier: 0.0
Armor Factor 16 1
Internal Armor
Structure Value
Front 2 6
R/L Side 2/2 3/3
Rear 2 2
Rotor 2 2
Weapons
and Ammo Location Tonnage
Booby Trap Body 1.5
Drone Operating System Body 2.0
ECM Suite Body 1.5
Since it costs more, the bang/buck is about a factor of 2 worse and it's a bit slower, but still exceptionally fast compared to most units. Deploying several Suicide VTOLs with a Suicide ECM VTOL could ameliorate this.
You also need a control vehicle. The obvious choice is another VTOL based on the Suicide ECM, something like this:
Suicide Lord VTOL
Mass: 15 tons
Movement Type: VTOL
Power Plant: 115 Fuel Cell
Cruising Speed: 151.2 kph
Maximum Speed: 226.8 kph
Armor: Standard
Armament:
Manufacturer: Unknown
Primary Factory: Unknown
Communication System: Unknown
Targeting & Tracking System: Unknown
Introduction Year: 3145
Tech Rating/Availability: E/X-X-X-E
Cost: 338,250 C-bills
Type: Suicide Lord VTOL
Technology Base: Inner Sphere (Advanced)
Movement Type: VTOL
Tonnage: 15
Battle Value: 108
Equipment Mass
Internal Structure 1.5
Engine 115 Fuel Cell 5
Cruising MP: 14
Flank MP: 21
Heat Sinks: 1 0
Control Equipment: 1.0
Lift Equipment: 1.5
Power Amplifier: 0.0
Armor Factor 24 1.5
Internal Armor
Structure Value
Front 2 8
R/L Side 2/2 5/5
Rear 2 4
Rotor 2 2
Weapons
and Ammo Location Tonnage
Drone Carrier Control System (5 drones) Body 4.5
So, 4 Suicides, a Suicide ECM, and a Suicide Lord pack into 70 tons, can deliver 515 damage to virtually any unit reliably, cost 2.325M, and have a BV of 522. Alternatively, 5 Suicide ECMs and a Suicide Lord pack into 90 tons, can deliver 575 damage, cost 4.09M, and have a BV of 838. Overall, it definitely seems overwhelming, and I don't see a good counter.
Update: changed Suicide ECM and Suicide Lord to 15 tons.