I like currect system for Ered Luin. I think this heroe group(similarly like Black riders) would be suitable for Erebor. Maybe Dain or Gloin(on level 10) can summon permanently or temporarily all surviving members of Thorin company (Dwalin, Bofur, Bifur, Dori and Nori). I think rest of the Thorin company probably also defended Erebor against easterlings in book. xD
Of course, they should have gray/white hairs and beards. Also, they can have Erebor armor from movie:
(http://media.moddb.com/images/members/1/762/761504/Dwalin_Heavy_Regal_Armor_-_Front_Back.png)
(http://media.moddb.com/images/members/1/762/761504/Dori_heavy_Regal_Armor.png)
(http://media.moddb.com/images/members/1/762/761504/Nori_Heavy_Regal_Armor.png)
(http://media.moddb.com/images/members/1/762/761504/Bofur_Heavy_Regal_Armor_Weapon.png)
(https://s-media-cache-ak0.pinimg.com/736x/77/c9/9b/77c99b2a5a6727771c5ed90e5eac4bbe.jpg)
Well I do not think the Summon Buildings is fiting so much may be a Summon a Battalion of Each Possible Dwarven Kingdom at the time,2 Battalions at once,Ered LUin,Iron hills,Grey Mountains and erc! :)
I think Gloin should summon them that is what I meant! :)
Oh, sorry. I guess you are right this summon would be better for Gloin on level 10. I think this battalion should have five abilities. One ability for every character in the group(Dwalin, Bofur, Bifur, Dori and Nori).
If I know Dain(iron Hills version) has very similar ability on level 10. But I have a solution and new ability for Dain in Iron Hills: 8-)
Dain(Iron Hills version) can summon only temporarily one battalion Ram riders on level 10.
I'm a little improved my old idea: 8-)
Glóin already has an great abilities, so I think Dain is better choice for summon ability.
Now in 4.1.1 is Dain most expensive hero in Erebor. Also, I think that King Dain need something more unique on level 10 than building with units from three dwarven subfactions. These units are available in all dwarves subfactions. I have an idea for something more interesting for him:
King Dain(Erebor)
Level 10: Old Warriors
Dain summon legendary companions of Thorin Oakenshield to the last battle. He summon permanently hero battalion like Black riders.
The hero battalion contains these heroes: Nori, Dori, Bifur, Bofur and Dwalin.
I think rest of the Thorin company probably also defended Erebor against easterlings in book.
Of course, they should have gray/white hairs and beards. Also, they can have Erebor armors and weapons from movie:
(http://media.moddb.com/images/members/1/762/761504/Dwalin_Heavy_Regal_Armor_-_Front_Back.png)
(http://media.moddb.com/images/members/1/762/761504/Dori_heavy_Regal_Armor.png)
(http://media.moddb.com/images/members/1/762/761504/Nori_Heavy_Regal_Armor.png)
(http://media.moddb.com/images/members/1/762/761504/Bofur_Heavy_Regal_Armor_Weapon.png)
(https://s-media-cache-ak0.pinimg.com/736x/77/c9/9b/77c99b2a5a6727771c5ed90e5eac4bbe.jpg)
Old Warriors abilities:
Level 1: Spear
Bifur throw spear against enemies.
Selected enemy unit or hero gets moderate damage.
Level 3: Thief
Nori is an experienced thief. He steals resources from the selected enemy building.
Level 5: Professional warrior(passive)
Dwalin is professional warrior and inspires dwarves on battlefield.
Nearby dwarven units gets more experience from slain enemies and resistance to fear.
Level 7: Wine
Dori gives the wine his companions. Old warriors will restore half of their health.
Level 10: Bofur's speech
Bofur tired of enemy with his speech.
Nearby enemy units gets -20% armor and -15% speed.
One ability for every character in the battalion. You can have only one battalion in game.
What do you think about this idea? 8-)