The forgotten Force Organisation slot? It certainly seems that way with Imperial Guard and Elites yet there are some good choices here. I remember when the first codex first dropped people were taking Psychic Battle Squads left right and centre (myself included) with Marbo for flavor. Now, we rarely see either despite Marbo still being an excellent and cheap choice. We all remember the rage over Ogryns and cries of cheese which quickly dwindled away and the poor Ratlings were oft forgot. Let's break each unit down and see whether or not this slot has been forgotten for a reason.
Ogryns:
All you need to know about these guys is they are T5 and W3. They're tough and decently durable but not exactly cheap. They have decent output with 3A base backed up with WS4, strength 5 and furious assault (but I3 on the charge) and an assault three, S5 gun with 12" range. They are obviously meant to be used in close and thanks to T5, do this quite well. T5 is important as they don't die horrible deaths to most powerfists (Thunderwulf cavalry excluded) and with Stubborn can bring a unit which is semi-decent at combat. They aren't great and will still fold to anything halfway decent in combat but it won't be quick and it won't be easy. The problem is they are expensive - even a squad of five costs 210 points + Chimera. For that price you can get 30 Guardsmen + Commissar + some upgrades in that squad and whilst not as durable, you've got more bodies, better Stubborn Ld and some heavy weapons to boot.
Ogryns are nice but miss the mark for their cost and find themselves a hard fit in an army based on ranged shooting.
Ratlings:
Ratlings have terrible stats but come with a Sniper Rifle, BS4, Stealth and Infiltrate for 10 points. The Infiltrate is key to making these guys anywhere near useful as you can deploy an infantry screen outside of your deployment zone. Add in Stealth and they are pretty durable in cover with a 3+ save and can disrupt your opponent's advance. Being 10 points a model and only needing a minimum of three keeps the unit cheap with the only downside to this role being they cannot score. If you're looking for a unit to disrupt the opponent Ratlings are decent enough for this and cheap but aren't bringing a ton of firepower to the table and if anyone gets with spitting distance of them, they'll die.
Psyker Battle Squad:
These guys used to see a lot of use but less so now. Why? Ld9 and psychic hoods mean they don't cast as regularly as you want and their whole damage potential is tied up in their ability to cast psychic powers. That being said, both of their powers are 36" range and can be used on the move. Put these guys in a Chimera and they should be able to avoid psychic defenses and cast away. The Chimera of course can be suppressed but the models inside can hop out and use Soulstorm or stay inside and cast weaken resolve.
So are the powers useful? Absolutely. Soulstorm is impressive against infantry and should wound most things on a 2+ if you have enough psykers. The random AP is annoying but most things have cover anyway so not getting low AP isn't the worst. If there are no infantry on the table being able to throw high strength blasts at tanks isn't terrible but certainly not reliable. Weaken Resolve on the other hand is full utility. Basing an army around this is a bad idea but being able to virtually force a unit to flee from shooting damage is a nice concept. Remember though, utility only. The PBS has a major advantage over other psychic squads in that D3 psykers die on a perils rather than the whole squad (looks at GK psykers).
In the end PBS are still a good unit, both on foot at the back of the army and in a Chimera (my preference is a Chimera, extra protection and firepower dur). Although psychic defenses weaken their ability to operate to some extent, the range and mobility of the unit should ensure they avoid them as much as possible. The question becomes, do you need the blasts and utility they bring?
Storm Troopers:
As SandWyrm said, why weren't these guys allowed as Troops through FoC swapping? Oh well. You don't often see Stormtroopers as they aren't exactly cheap for Imperial Guard. 16 points a model on a T3/4+ model is pretty expensive even with their special toys and AP3 gun. Their ability to deploy in special ways and get two specials for five guys however, is reason enough to take them. Let's look at their Special Operations.
Reconnaissance - Scout and Move Through Cover. Nice but without Infiltrate and Stealth you're really only getting a free 6" move outside of a Chimera. No thanks.
Airborne Assault - Re-roll scatter dice when you deep-strike. This makes deep-striking much more reliable and with the option to take a couple meltaguns, sounds good.
Behind Enemy Lines - Infiltrate + their weapons are pinning the first time they are fired. Infiltrate is nice but I'd like some Scout and Stealth to go with please! Pinning the first time they shoot is pretty eh. For the whole game would be nice but once is unlikely to do anything.
With this information I'd nearly always being going for the Airborne Assault route and grabbing a couple meltaguns. They become are reliable suicide unit with BS4 and krak nades which can drop anywhere on the board and combined with an Astropath, come in pretty early. This frees up your other melta units to not need to push forward too aggressively and allows the rest of your firepower to focus on midfield threats rather than trying to take down backfield tanks.
Stormtroopers also come with AP3 lasguns which are an 18" rapid fire lasgun. Having AP3 is nice but not something you are going to take these guys for, they are just too expensive to get lots of guys in a squad and with strength three, aren't going to do too much damage anyway. Add in cover being super common in 5th edition and those couple of wounds you inflict on Space Marines still get a 4+ save. If you aren't taking these guys for their two weapons per five guys in a small squad, I probably wouldn't be taking them as they are just too expensive.
Conclusion:
When we look at the Elites Imperial Guard has available to them compared to other armies, we can see why it's not used as much compared to other armies. Although Psychic Battle Squads and deep-striking melta Storm Troopers are pretty decent choices and don't break the bank, PBS have limited use against mech armies and don't like the frequency of psychic defenses whilst Stormtroopers are pretty expensive for a five-man squad but do bring good disruption. Ogryns and Ratlings are found a bit wanting though do have roles themselves and Marbo as we discussed in the previous post, is always a good buy for cheap disruption.
