Which is my point, doubling the capacity at the end of the spear is more than double the burden. The scale is superlinear. The further out the front is (for the US, it's over at least one ocean), the more superlinear the scaling is.
> but it's not proportional to cost
You might've heard of the cheap North Korean shells exploding in barrels, destroying Russian howitzers. It is indeed very disproportional, that's why spending severalfold on better shells is a great tradeoff.
> You'd launch two at the same time to take the possibility of failure into account
It depends on the ability to launch two. Oftentimes it's impossible; cheap FPV drones interfere with each other, or maybe you don't have double the planes to fly CAS.
> how they are being employed today in Ukraine
It's logistically impossible to employ the kind of drones Ukraine is employing on the go and organically to infantry. Features and CONOPS that enable organic employment lead to a substantial increase in per-unit prices, see Rogue 1.
> A Magura isn't a missile, but it has shown its capability of completely shutting down the Black Sea Fleet.
It's three Black Seas worth of distance between Guam and the Taiwan strait. On top of that, nowadays those boats are pretty effectively countered. Overindexing on the war in Ukraine would be a mistake.