One thing is for sure that removing the cockpit and life support and the human element and large bomb bays, one can make the drone even stealthier and potentially even longer ranged.Uncrewed “wingmen” for the Air Force’s next bomber and fighter will be large, sophisticated and costly.aviationweek.com
mass = $$$
Loyal wingman for B-21 probably doesn't need the same payload as B-21. Does it make sense to build a baby B-21 with maybe a 5000kg payload? Or do you build something smaller with a payload of ~2500kg?
And since you should be able to send these drones to a point in space, they dont need to leave with the bomber flight. They can be picked up wherever. The point being they won't require high subsonic speed. They can leave earlier or from a different location, be in the air already and assemble at a given location. Perhaps you also have the ability to deploy from odd locations; highways, small islands, even aircraft carriers if it makes sense. Smaller and lighter equals less runway required.
Sure, you could always just send another B-21. If the objective is ordinance to an objective for a price then perhaps you go smaller and slower. Maybe a less expensive engine with a higher TBO - reducing maintenance costs and allowing more time in the air. Perhaps you build it for hose-and-drogue refueling as well. A smaller airframe doesn't need high refueling rates and forward deployed perhaps it gets fuel regularly from C-130's and even MQ-25's.
If it's smaller, slower, and much cheaper, then perhaps you build more. Building more, by itself, creates additional cost reductions. F-35A is down to $80m.
How inexpensive can I build a drone with B-21 type stealth, a payload of 2,500kg and a range of 4,000 miles? MQ-25 is $150m per copy. If NG built it, perhaps half that? (Only partially tongue-in-cheek) But if I built several hundred of only slightly different variants then my costs come way down. Perhaps some have a focus for B-21 missions, others carry munitions for HAVCAP fighters for tankers and ISR platforms. Still others may originate additional munitions for F-35C carrier strikes from further behind the lines, extending the reach and punch of the CSG.
It's a bit fanciful. The one thing I agree with Stalin about is that 'quantity has a quality of its own.' Several hundred stealthy drones constantly ferrying munitions to battle like a conveyor belt would be a very welcome tool in my opinion.