~snip~
This weapon deals a fairly significant amount of damage at a huge range, because the final stage swarm missiles are really fast and small. However, there is inescapably overkill issues unless the final stage swarm missiles have a sensor too. Doctrine wise, you lose a LOT more payload per missile for small missiles having sensors compared to larger missiles. But for something that operates like a mine, perhaps the final stages HAVE to have some sensors no matter what.
The bus or mine can launch its sub-munitions via passive sensors. However, the sub-munitions will also then need their own sensors whether they be passive or active.
So tactically and strategically, what sorts of counters are there?
Counters to this doctrine? CIWS, longer range amm, and having a small sensor signature from cloaking and thermal reduction.
Detecting the missile in its stage one phase seems impractical, maybe if you have a sensor platform close to the enemy when they launch, you can vector some fast fighters with AMM to take them out.
I think you have it backwords. The first stage is the easiest to spot, and normal nprs can usually sopt these a few million km out.
Stage 2 can be detected by seeing its emissions, but chances are it will already be inside its range at that point.
But defensive fire can still shoot.
A lot depends on where it is being used. In a warp point fight where the targets are on the warp point, jumping out is an option. Just jump back in outside of the myopic sensor ranges of the swarm. So defending a warp point with these would be problematic vs a human player.
You're forgetting about jump shock which disables both sensors and jump engines when completing a jump for several minutes.
Might be kind of fun to station these defending a warp point from the attackers side, because they are fire and forget. Launch and retreat, using them to damage an attacking force without much fear of being damaged in turn, at the expense of conceding the attackers' side of the warp point.
They aren't quite as fire and forget as you think. You really need to manage your waypoints and such when trying to lay these. When it gets close enough to drop the "mine", it should also be close enough that it wants to fire the smallest stage. But if you remove the waypoint to soon, the largest stage wont drop the mine and will simply self destruct.