So my general plan is to go through each of the sections of the force org chart and discuss the units that *I* feel could/should be included in a Loganwing, and discuss their relative merits. The decisions you make in one part of the Force Org have significant impacts on the rest of the build. Everything in a Loganwing (and in any army really) should work together with each piece playing its part. Let's start with HQ, shall we?
HEADQUARTERS:
Oh boy, HQ!
Space Wolves can take up to four of them. You are already sinking a lot of points into HQ just by taking Logan, but the Wolves are an army that can, in my view, get away with having a few really "meaty" characters in their army. Let's talk about some other heroes who might want to bask in Logan's glory:
Wolf Lord
I can really only see one use for a Wolf Lord in a Logan army, and that's putting him on a Thunderwolf and using him as a counter-assault badass. Saga of the Warrior Born, Runic Armor, Storm Shield and a Wolf Claw. Rawr. I have played with this guy and he lives up to all expectations. Pro tip: the bonus attacks last until the next player's assault phase, so it's especially important with the Wolf Lord NOT to have him defeat his enemy's on your turn. Instead, you want him to beat them up a bit, get some bonus attacks, use those bonus attacks on the next turn to wipe them out, and then charge into another combat. He can roll around with a Fenrisien Wolf pack escort, a Thunderwolf Cavalry escort, or a hybrid (Thunderwolf Cav with a couple of "wargear" Wolves as ablative wounds. If you want a fast choppy element to your army, this is one way to go.
If you are looking for a foot-slogging character to drop in with Logan, Arjac is just a plain better choice. We'll talk about him too.
Rune Priest
The Wolves get, hands down, one of the best psykers in the game. While not a "killer," the Rune Priest does what I feel psykers OUGHT to do, which is to provide excellent support to their army. The Rune Priest also provides one of the best psychic defenses in the game as well, making him a double threat.
Most psychic powers are only effective against "troops in the open." Many armies can get away with not having defenses against these powers because they have enough transports to keep their troops from being targets, at least for the first portion of the game. Not so with Loganwing. You are out there in front of god and everyone, which means some psykers will really give you a bad day. For that reason alone having a Rune Priest is generally advisable. I am not going to say it's a "must have" (my goal here is not to tell you the "one" way to do a Loganwing, but instead to give you some tools and thoughts I have gathered over time), but if you get a Rune Priest, you will find him useful as a defensive tool.
The other big thing that the Rune Priest brings to the table, in my view, is his movement control abilities. Murderous Hurricane and Tempest's Wrath provide good tools for slowing your opponent down. An example of Murderous Hurricane as a tool is to bring Logan's unit within 12" of a Land Raider (right at like 11.5") and actually separate off the Rune Priest so he is a solo unit at the end of the movement phase. You can them use your Multimeltas to pop the Land Raider, and then case Murderous Hurricane on the Assault Terminators inside. The terminators will be rolling difficult terrain in the movement phase and another difficult terrain check in the assault phase. Chances are that they are going to fail to assault your unit if you do it right. This tool works wonders with Ork Boyz, Tyranid swarms, and pretty much anything that you want either slowed down or taking lots of dangerous terrain checks. It can even force dangerous terrain checks for vehicles and walkers, so if you have no other targets don't be afraid to his even Land Raiders with Murderous Hurricane. Remember that the only way to target a unit that you are blowing out of a transport is to separate out the Rune Priest at the end of the Movement phase. Remember also that this is a risky proposition, but may be worth it in certain circumstances. Just another tool in your toolbox.
Njal Stormcaller
This guy does everything that a Rune Priest does, but better. Access to all of the powers plus the ability to cast two per turn make him the ultimate Swiss Army knife. Plus his 3+ Rune Weapon tends to turn enemy psykers into huge wastes of points (Lol Grey Knights?). Having used him in a tournament setting, I can attest that he is one of the few "uber psykers" that can actually be worth his points.
Since the Space Wolves FAQ, he is slightly less powerful, as some of his best special powers do not function at all if you are going second. That is really too bad, and for that reason I don't feel Njal really works well with a Loganbomb list (which often wants to go second). We will talk more about that later.
But make no mistake, he is a pricey character and with him and Logan you are already over a quarter of your army into two characters. Better make sure you know what you're going to do with them. He is still only two wounds and will still die like a Hooch if you put him in the wrong place. Keep him safe but in a good position to use his powers and you can get your points worth.
Wolf Guard Battle Leader
If I don't like a Wolf Lord on foot, why would I like a Wolf Guard Battle Leader? Well, simply put, because they can do something that's relatively unique, which is to grant any unit they attach to Stealth. Yes, a WGBL with Saga of the Hunter grants Stealth to his unit. He can also take two Fenrisien Wolves. Now if his unit is in cover, everyone in the unit effectively has a Storm Shield against low AP weapons. This also means that Fenrisien Wolves have that same wonderful 3++ save and that Logan can suck up Lascannon shots against a 3++ cover save, which helps him to absorb more of those shots so his unit can survive.
Giving a WGBL a Frost Blade can be a worthwhile investment as well. He and Logan are both going to be striking at I5, and he will have 5 attacks during the first round of combat (6 if Logan pops his "feat"). This means that if, for example the unit is charged by something striking at I4 or less, that unit will take between eleven and thirteen attacks which are hitting on 3's in most cases, rerolling misses, and wounding on 3's. That will gut units like TH/SS Terminators before they ever swing.
Additionally, giving him a Frost Blade allows him to, if you so desire, attach to a Wolf Scout unit and go chopping through your enemy's backfield. Options are good to have and against Tau for example, that is a nice one to have.
So we've got some pretty nice tools in the HQ section, all of which do more than just add choppy to the army, they each provide support and synergy which help the army as a whole to operate more effectively. Any of the above could be valid choices, it all depends upon how you want to build the list.
I intended to get into Elites during this post, but it's going to have to wait until next time. This series might take a while, as I am data dumping a lot of experience playing this army in 5th. I hope that it is helpful to someone out there.