I'm always a fan of adding more things for Adventuring fellows. Seems like an Untapped area of play. To hell with people who don't like Adv Fellows.
Adding 1man and 3man "BCNMs" for Adventuring Fellow would be fun, To add something more, this could make a lot of sense from Luto's perspective.
Luto is for all intents and purposes like Naja, Except less evil. Shes a "hired arms" type person, Thats what your NPC does, works for Luto. It could easily be, after level ~50 (maybe make a low cap for it) you could get a quest to activate doing this "missions" for Luto. Obtaining Orb through Fellow Points from the Near-eastern NPC, and then doing the battlefields.
Would be really fun idea... Each BCNM doesn't need super rewards, Just basic Synth Junk, some NPC Armor, and maybe 1 Unique Item per BCNM. could be a lot of Level caps too (Well not a lot). One 3man and one 1man for a few level ranges like:
50 - (5,000 Fellow Points per orb)
60 - (8,000 Fellow points per Orb)
75 - (10,000 Fellow Points per Orb)
90 - (15,000 Fellow Points per Orb)
99 - (25,000 Fellow Points Per Orb)
Each Battles could grant armor specifically for improving the NPC (That works when Summoning and does not need to remain on). Like
50 Cap armors. -
----------------------------------------------
*Fellowship Cap
lv.50
Adv. Fellow: Adds Refresh Effect.
Cure Potency +2%
MP+15
*Fellowship Briault
Lv.50
Adv.Fellow: Adds Regen Effect
Cure Potency +3%
Cure Spellcasting Time -3%
MP+10
Fellowship Mittens
lv.50
Adv.Fellow: Cure Spellcasting Time -2%
MND+3 INT+3 MP+10
Fellowship Brais
Lv.50
Adv.Fellow: MP+25 HP+25
Cure potency +2%
Fellowship Gaiters
Lv.50
Adv.Fellow: MP+10 HP+10
MND+2 INT+2 Macc+4
----------------------------------------------
This is an example of a "mage" type set. relatively low level so you can use it early on. These armors would drop from the 50, 60, and 75 BCNMs. There would be a Melee, and Tank set for each too....
As for the level 90/99 Cap fights, There would be armors for slightly higher level Adventuring Fellows! like the follows
------------------------
Fellowship Mask
Lv.99
Adv.Fellow: HP+45 Haste+3%
Accuracy +5 Attack+5
Weapon Base Damage +20%
Fellowship Hauberk
Lv.99
Adv.Fellow: Haste+2% STR+10
DEX+10
Quad. attack +1%
Fellowship Gauntlets
Lv.99
Adv.Fellow: Haste+3% STR+5
Accuracy +10 Attack+10
Fellowship Subligar
Lv.99
Ad.fel: Haste+3% DEX+4
Accuracy+4 Critical hit Rate+5%
Fellowship Leggings
Lv.99
Ad.Fell: Haste+4% VIT+5
Critical hit Damage+5%
-------------------------------------
Fellowship Helm
Lv.99
Adv.Fellow: HP+50 VIT+10 Haste+3
Damage Taken -5%
"Shield Master" +5
Fellowship Cuirass
Lv.99
Adv.Fellow: HP+100 VIT+20 Haste+3
Damage Taken -10% Enmity+10
Fellowship Bracers
Lv,99
Adv.Fellow: MP+100 MND+15
Cure Potency +20% Enmity+15
Fellowship Cuisses
Lv.99
Adv.Fellow: STR+15 DEX+15
Accuracy+20 Attack+20
Weapon Base Damage +25%
Fellowship Greaves
Lv.99
Adv.Fellow: DEX+10 Haste+7%
"Shield Defense Bonus" +5
Damage Taken -5%
These buffs, While looking broken on paper, would actually just make our Adventuring Fellows a little more powerful. You have to remember they dont get Food buffs, or all the rings/earrings buffs we get. If anything the above will make the Melee Adv.Fellow a bit more appealing. It won't break them, Just make them a step up from "Suck City".
Also, The 90, 95, and 99 BCNMs would Each be used to obtain the "Final" Armor for your NPC, Which I show 2 of above. This wouldn't be a random Drop method, Each time you win the fight, You'll get a KI you can trade to Luto for 1 Piece of the Armor. The Armor is R/ex, and would eventually be storable by Mog Slip!
This would take a lot of Development time though
Edit:
Also, Some example of the Unique Items could be(I used the phrase A.F.S A lot, that means "When your Adventuring Fellow is Present (Summoned):
Bond Earring
Level 50 (R)
HP+15 MP+15
A.F.S: Accuracy+3 Attack+3
Bond Ring
Level 60 (R)
MND+2 INT+2
A.F.S: Cure Potency +3%
"Magic Attack Bonus" +1
Fellowship Cape
Level 75 (R):
STR+3 DEX+3
When Adv. Fellow Sumoned: Accuracy +5 Attack+15
Fellowship Chain
Lv.80 (Neck) (R)
DEX+3 Accuracy +1 Critical Hit Rate +3%
A.F.S: STR+3 Attack +1 Critical hit Damage +3%
Luto's Charm
Lv.85 (Ammo) (R)
STR+1 DEX+1 VIT+1 AGI+1 INT+1 MND+1 CHR+1
Accuracy +2 Attack+2
A.F.S: All Stats +3 (Additive)
Eternal Bond Charm
Lv.90 (Neck)
MND+5 INT+5 CHR+5
A.F.S: Magic Accuracy +5
"Magic Attack Bonus" +5
"Cure Potency"+5%
Eternal Bond Belt
Lv.95 (Waist)
STR+3 DEX+3 Critical Hit Rate +3%
A.F.S: Haste+6%
Eternal Bond Ring
Lv.99 (R)
STR+5 DEX+5 VIT+5
A.F.S: Accuracy +5 Attack+5
Triple Attack +1%
Quadruple Attack +1%
Most of the Above would remain "Mediocre" At best unless your NPC is summoned. Since NPC's can only be summoned in a limited number of places, and only for a short period, Its not like the armor is took broken. There could be 2 Types of "Rare" Armor for each Level Range. One from the Solo BCNM, one from the 3-man BCNM. One could be designed toward a Melee, the other a Mage.