- firstly, planets are big and ground units can hide and evade using terrain relatively easily.
Well I thought that's what FFD was for? And yet even with them you kill almost nothing.
FFD is for being able to shoot in the first place.
I thought you could just indiscriminately bombard the planet and hit enemy troops by chance, but FFD let you add ships as supporting elements to your ground forces, allowing them to work like artillery?
There are two ways for ships to shoot at planetary ground forces. Technically three, since missile fire uses different mechanics, but we'll keep it simple:
- They can just target the planet, fire their guns, and reload. Repeat until something is dead.
- They can fire in support of a friendly ground formation with FFD. The advantage of this is an increase in accuracy (I believe a factor of 3) which implies a decrease in collateral damage and dust production. The disadvantage is that the ships will only fire once per ground combat increment (8 hours) instead of at their usual ROF, which is why this option tends to be underwhelming in practice.
FFD works fine if you use ships with a large number of guns to support, and don't expect a huge contribution from the orbital forces, basically treating them as additional artillery while your ground pounders do most of the work. If your goal is to wipe them out as quickly as possible, you'd just use the first option, indiscriminately bombard the planet into slag, and leave trivial things like "dust", "radiation", and "the planet being completely uninhabitable" for the politicians to argue about.
Note that there is a salient economic difference here as well. Using the ground forces with orbital support means you'll take heavy ground force losses, which cost vendarite to replace. Using indiscriminate naval bombardment costs a lot of MSP, which costs duranium, uridium, and gallicite. Since the latter three minerals are usually more valuable, using ground forces represents a higher cost in human lives in exchange for conserving your more valuable mineral types (the MSP used by orbital supporting fire is considerably less).