I have been thinking about Stormblade Infantry in the new edition.
First, I will skip the part about positioning or formation, because MadJack already made a great tactica in MKII era. Although their ability has changed, the idea of positioning or formation still works except for their RNG 0.5 Melee range in MKII.
I am not good at English so sorry for the broken English. And thank youpraetordave! He helped me to fix bad grammar(is it wrong, too?).
I am not very skilled, but I have used them in the MKII era so I have had some experience with them. Although they have been tweaked somewhat, their main purpose remains unchanged.
Stats and Abilities
Basic Unit: Only 6 troopers, 1 Leader and 5 Grunts. Same price as a minimum unit of Trencher Infantry.
-Stats: SPD: poor, MAT: good, RAT: poor, DEF: poor, ARM: good, CMD: moderate.
-Advantages: Combined Melee Attacks , Immunity: Electricity .
--Ranged Weapon: RNG poor, ROF 1, POW: Good.
--Melee weapon: RNG 1, and POW: capable. Leader has RNG 2 melee weapon (only for him, and every other models in the unit cannot have it).
Leader has an ability that gives +2 to RNG and +2 to melee and ranged attack damage rolls for the other troopers in the unit within 5" of himself.
Officer&Standard Bearer: Command Attachment.
-Stats: Officer has +1 MAT/RAT. Standard Bearer shares the normal grunt statline.
-Advantages: same as the base unit; in addition, the Officer has 'Jack Marshal and Officer.
-Weapon: same as the basic unit.
Officer has Granted: Assault and Iron Zeal(once per game, gives +3 to ARM and immune to knocked down and Stationary to the unit for one round). The Standard Bearer is considered a Stormsmith Stormcaller when using a Surge or Triangulation Stormcall, is a Standard Bearer and has Take Up.
Storm Gunner: Weapon Attachment.
-Stats and Advantages are same as the basic unit.
-Weapon: Ranged weapon has medium RNG and POW equal to the troopers. Melee weapon is identical to troopers.
Ranged attacks made by the unit during their activation automatically hit the same target already hit by the stormgunner.
They are the basic Weapon Master unit in Cygnar, similar to Knights Exemplar, Doom Reavers, Bane Thralls, and Dawnguard Sentinels. They are slow, a bit fragile, and hit hard.
While they have other advantages, Stormblade Infantry have a ranged weapon, though their RAT and RNG are poor. However, if you are able to bring up their RAT and/or RNG, they can earn their points back.
Anti-Armor Melee Unit is their primary role, and it is their most important. They can cripple or even destroy ARM 20 or less jacks and beasts with ease. They can chop so called 'heavy infantry' (non-cavalry 3-6 man units with damage boxes) too. They can cause serious damage against ARM 21-22 too, and you don't see a warjack/warbeast with ARM 23 or more very often.
Also, if you can afford a ranged accuracy buff, they can kill infantry without needing to get into melee with them. Because of their fragility, it is good to have a bit of distance between the enemy following the attack. After all, if you don't need to charge, or cannot charge, you are better off shooting. So, with an accuracy buff they can kill infantry and jacks/beasts alike. It doesn't mean that they are not good at killing infantry in melee, since their MAT 7 is enough to hit most troopers.
They are bad at standing their ground or taking the front, due to their victim stats and slow speed. If you have need for such a role, you’re better checking out Trencher Infantry or Sword Knights. Stormblades can withstand some attacks with a buff, but they are not well suited or costed for that.
You may use them to fuel a Stormclad. While not very effective only for this, a minimum unit can earn 10 points when you do this well. But I recommend trying this only if you have two or more Stormclads.
Their Officer is a 'Jack Marshal but he have no Drive. So you are better off giving the jack to Archduke Alain Runewood instead if you need a marshaled warjack. Just keep in mind that he can take control of an autonomous warjack or wake up an inert warjack.
What size unit is necessary to use them properly? - The uses of the Attachments.
At the very least a minimum unit can do enough work to earn their points (10). They will not do a great job, but they will do well considering their points. I don't recommend providing buffs to a minimum unit. If used as a minimum unit, use them as a focus battery for a Stormclad or use them as a counter assault force.
If you have enough points and you want them to take some part in your list, the first thing to do is to add the Command Attachment. The Officer is the basic requirement to use them well, for he gives both Assault and Iron Zeal.
Assault is good to give them more threat range, only making ranged attacks when they fail a charge but still giving you more options. It also slightly helps to crack armor too. An unboosted POW 14 shot causes about 1.555 average damage to ARM 20 target. It may be viewed as superficial, but remember that the Officer grants Assault to the unit and the model still makes the ranged attack even if it failed the charge. Only about five troopers are able to make it into melee against a 50mm based model, but all of them are able to make a ranged attack. If you add all the attachments, a Stormblade Infantry unit will have 11 troopers. If you can keep all of them alive, when you order them to charge a target the whole unit can cause about 12 damage solely through ranged attacks, assuming 5+ to hit and does not count for auto hit by Storm Gunner. With assault, their actual damage output is much higher than you imagine.
All Stormblade Infantry have Immunity: Electricity, so don't worry about missing the attack and hitting your peers. Just shoot them anyway, unless there will be another friend without immunity nearby.
Pop Iron Zeal as soon as they get into range of taking some hits. Pop as soon as possible and reduce the initial losses.
The Stormblade Storm Gunner is also great, though not required. If you add one or more of them, you can have longer RNG and he helps them concentrate on a target with the ranged attack. Although their RNG is too short to easily make use of auto hits, automatically hitting is still a good effect. Consider the Storm Gunners additional bodies, since you cannot add more grunts.