I am posting this old AiMe thread from the old forums, as it might be helpful for a discussion or for Reference.
What Classes and Levels are the Fellowship
Aragorn: Dunedain,Fallen Scion, Scholar 3 (Healer) /Wanderer 13 (Hunter of Shadow)
Boromir: Men of Minas Tirith, Oathsworn, Warrior (Knight) 15
Legolas : Wood Elf, Emissary, Warrior (Weaponmaster) 14
Gimli: Dwarf, Emissary, Warrior (Weaponmaster) 12
Hobbits From the Shire to Rivendell
Frodo for me is much more experienced than the rest of the Hobbits.
Frodo - Hobbit, Fallen Scion (More like just a Nobel) Wanderer 1, Treasure Hunter 2
Sam - Hobbit, Loyal Servant, Warden 2
Merry - Hobbit, Lure of the Road, Warrior 2
Pippin - Hobbit, Lure of the Road, Warrior 2
Hobbits By The Scouring of the Shire
Frodo - Hobbit, Fallen Scion (More like just a Nobel) Wanderer 1, Treasure Hunter 10 (Agent)
Sam - Hobbit, Loyal Servant, Warden 10 (Herald)
Merry - Hobbit, Lure of the Road, Warrior 10 (Knight)
Pippin - Hobbit, Lure of the Road, Warrior 10 (Knight)
What Classes and Levels are Thorin &Co.
Bilbo Baggins- Hobbit, Reluctant Adventurer, Treasure Hunter 1
Bilbo Baggins (End of the Hobbit)- Hobbit, Reluctant Adventurer, Treasure Hunter 3 (Agent), Warden 3 (Counsellor)
Not much can be said about the 13 Dwarves, if we base our considerations exclusively on the novels.
Thorin was the leader and a dwarf of royal lineage, so you would expect the highest level and Charisma score in the company. Which class enjoys high Charismas scores? Probably a Warden, or a multiclass Warrior/Warden.
Balin was the oldest, and "always the look-out". So he should have the at least same level as Thorin, and the highest Perception bonus in the company, which means the highest Wisdom score. Which class benefits from high Wisdom scores? Well, everybody, but most of all probably a Wanderer, Scholar or Warden, or a multiclass between them.
Fili and Kili were the youngest, and always the scouts. So they should be of lower level than most of the others, and have high Survival and Investigation. They are probably Wanderers, or multiclass Wanderers/Treasure Hunters.
Of Dwalin we only know that he's a good warrior, and that he died very old. This could mean a fairly high level and a high Constitution score, which qualifies him either for the Slayer or the Warrior class, or a multiclass Warrior/Slayer.
Of Bombur we only know he is the fattest, so probably a good Constitution score and a low Dexterity... but he also held his own against the three trolls, as he is said to have given "a lot of trouble and fought like mad". Sounds like a Slayer...
Of Dori, Thorin stated that he was the strongest of the Dwarves in the company. Good Strength means a good combatant, so I would say a Warrior or Wanderer. Not a Slayer, because Bilbo proclaimed Dori to be "really a decent fellow", so not exactly how I would expect a Slayer
Óin and Glóin were noted for their ability to start fires, and nothing else. Probably low-level Wanderers.
Bifur and Bofur are only noted as Bombur's relatives, while Ori and Nori have no description whatsoever. So we have complete freedom on them, but still they can be considered very low-level characters, without notable abilities compared to the others.
Regarding the levels of each one, well, they are practically fleeing all the time so they probably aren't so much experienced... . I would say (completely my suppositions) 5th level for Thorin and Balin, 4th level for Dwalin, 3rd level for Bombur and Dori, 2nd level for Fili, Kili, Oìn and Gloin, and 1st level for the others (Bifur, Bofur, Ori and Nori).