Wait, why do I want markerlights?
Trust me, you do. There are a few reasons you want them - some are unit/gear specific
1) Bonus to BS
2) remove cover saves
3) seeker missiles
4) Stormsurge destroyer missiles (because Strength D is silly at range)
Ok, ok, I'm sold!
Good, because you should be. Note that you're a shooty army that loves BS3 - as such, you really don't like missing or watching the other guy just duck you shots.
Seeker missiles are kind of TBD - most of your vehicles (and your Broadsides, if any) can take them, but you don't necessarily want to take a bunch of these.
Finally, note that your Stormsurge(s) pack four Destroyer missiles - they're S8 AP1 rounds that can upgrade to Strength D with Single Use. And honestly, why wouldn't you pay the upgrade them to 'D' when you have a 60 inch range? Figure on firing these at BS5 with a 'D' upgrade, which is 2 lights plus one per D missile.
So, where do I get them?
You have multiple sources of Markerlights - but they aren't all created equally. You can get Markerlights off of a variety of sources -
1) Markerlight Drones (NOTE - they're BS2) as wargear for various leader types and/or suits
2) Leader types (IE - Fire Warrior vet sarge types, Ethereals)
4) Drone Squads
5) Skyray missile boats
So, let's narrow this down a little, and talk about a crucial piece of gear - the Drone Controller.
Why Do I Care About the Drone Controller?
Very simple - the Drone Controller lets any drone hanging out with the owner use the owner's BS. Considering that drones are otherwise BS2, this is huge. A BS2 markerlight is sad; a BS3+ markerlight is worth considering.
So, what are my practical sources of Markerlights?
They're the classic markerlight source. Each guy in the squad has one. You have the basic Fire Warrior light infantry statline, with a bonus of Scout
They fit neatly into a hunter cadre, and with a Scout move you can react to the other guy's deployment a little. You can also get other weapons in there.
They're static, and it's not THAT hard to shoot them off the board or force a morale check. Also, anyone who's been playing for a minute knows what they can do. And while you COULD get other weapons in there (like an S7 gun, for example) those guns don't benefit from the markerlight.
If you're going to take them, take them as pure squads of markerlights, but be aware that they've got slightly better than a 50/50 shot to fail a morale check. And if they do, they run out of position (if not off the board) and are potentially useless for a turn or two, which is a Bad Thing.
These guys pack a pair of Networked markerlights. The 'networked' bit basically means that the Skyray can paint its own targets - which is important because it's toting a half-dozen Seeker Missiles.
You've got two BS4 marker lights - and they're on a well-armored platform. The other guy has to devote anti-tank assets to deprive you of markerlights, and in a pinch you could always jink - which means the other guy can just keep you jinking. You don't die, but again, BS1 markerlights are...um...useless.
They're difficult to get into anything other than a CAD - you've got to take either a Hunter Cadre or go Farsight Enclaves (Hunter Cadre OR Retaliation Cadre) and then grab a formation that involves them. That aside, you're paying a chunk for durabilty. Also, you're still not getting that many markerlights. Also, you have to keep track of how many missiles the thing fired, which is annoying to me at least.
So, here's where it gets interesting. And I really need to test these guys.
If you're going with a Hunter Cadre, you can take a unit of drones and satisfy your 1+ auxiliary choice. That being said, there are two other perks these guys have going for them - the drone controller, and jet pack infantry. You can get up to BS3 (if you're hanging with a Crisis Suit) or better (if you're hanging with a commander).
You're still stuck with the same durability as a Pathfinder, though probably not in cover. That being said, you've got a slightly better chance of hiding out of LOS because you can jump-markerlight-jump. Also, you are relying on a Crisis suit (or commander) to boost your BS. You could theoretically glom on to a Cadre Fireblade or something else, but your biggest defense is not being in LOS - which is a bit of a challenge with those commander types who AREN'T in a suit. Also, if you have one Commander means you might want to reconsider who ends up being the Warlord, since that Commander is going to be lending its BS to the drones. But hey, BS4 markerlights?
Look, you can grab a markerlight here and there if you're taking Fire Warriors and other units - but understand that without dedicated units, you're deciding to hand off fire one after the other. If you have a small Fire Warrior team with a
If you didn't know already, you should bring markerlights because you're a shooty army. That being said, you ESPECIALLY need them if you're going to get the most out of a Stormsurge's D missiles.
I'd recommend giving a Drone Commander a shot - Pathfinders can fit into an army, but need to be in position early on and are going to be a fire magnet. There's nothing wrong with carrying multiple sources of Markerlights, but you can easily fill out a Hunter Cadre with a Commander with Drone Controller and a Drone unit.