In this example, only ground units benefit. There are blankets, yes, but they're weaker.
In the new Dark Eldar, we get a similar feel. Lady Malys makes her unit immune to psychic powers. Duke Sliscus improves one unit's poison and gives you two choices of Combat Drugs. Baron Sathonyx makes Hellions Troops. Point is, not every unit in your army has the potential to benefit, so you'll want to tailor your list more.
Looking back at Space Marines, instead of this specific boost to certain units, some characters improve everything instead. Shrike makes you Fleet. Vulkan makes your anti infantry better (flamers) and your anti-tank (melta weapons, thunder hammers). Instead of being specific, these guys give you a blanket bonus.
Yes, you can tailor your list around Vulkan, but you don't have to in order to gain a decent advantage. Most Space Marine armies will have a couple of flamers or melta guns. There are few units that wouldn't be better with Fleet. On the other hand, taking Sathonyx with no Hellions, or Sliscus but no Warriors, is pointless, as you're not getting everything he offers you, therefore some of his cost is a waste of points. Malys is slightly different in that she's more tactics based than list-based. You'll want to put her somewhere she'll be really appreciated, rather than just with that random squad over there.
Thankfully, the Space Marines do have this sort of character too. Sicarius is like a Sliscus for Tactical Squads, offering one unit a benefit. Pedro Kantor benefits Sternguard. Even our old mate Lysander gives a specific bonus to his unit with Bolter Drill. I like these characters, because you have to put more thought into their use. I also like the old-style combat monsters, as they too gave a specific bonus, as whatever unit they are with is immediately more threatening, or the character is just a fire magnet on their own. But Shrike? More like "My army all Fleets, ha!" Instead of making you think about their use, anyone can slot them in and immediately everything's all better.
Hopefully you now see what I want Special Characters to become. Not an instant buff for an army, not something easily abuseable, but a completely new fighting style for an army to adopt. So with that in mind, look at the Codex in front of you, and choose your CO.
Hopefully I'll soon put up Part 2, where I shall attempt to rewrite Vulkan and Shrike to make them fit in better with my concept of the Special Character.
You'll also notice this bit's in a shade of green rather than red. This is because I, Master Bryss, can now post my own stuff rather than going through Atrotos first. He's currently working away at the Stellans so has less time to post. See you all next time.