Psychorocka, I enjoyed your post and it's a fair point that the fellowship's racial mix was essentially unique in the history we have, and that some combination of peoples are thematic while others are not.
OTOH, the nested post where you said that a Steward of Gondor, Rohan Warrior, and Dunedain Ranger made for a "mega unthematic" grouping I do disagree with. All three were involved in the Siege of Minas Tirith, and though they did not meet due to Denethor's self-immolation, they certainly could have -- and *would* have if Denethor had made different choices. It might be unthematic for the Hobbit saga, but I think it's actually a very thematic lineup for Flame of the West.
There's actually precedent between the Hobbit and the LOTR for Dunedain among the fighters of Rohan and Gondor. Aragorn served in both realms in disguise, and since the non-saga game is set between the two, in theory a Denethor/Aragorn [Thorongil]/Theoden grouping may have occurred in the historical timeline. Theoden was born in Gondor and the speech of Gondor was used in Thengel's house, it's no stretch to think young Theoden may have spent time at Mundburg serving Ecthelion, who himself sought out "all men of worth from near or far to enter his service".
Balin and Bard are only provided in the Hobbit saga, but of the 76 years between the two sagas, Bard lived for 35 of them and Balin for 52 -- that would make them available for quests that *could* be produced in the game period, though so far the cycles hint or state a period close to the beginning of LOTR. (If they are intended to all be in chronological order, and we place Dead Marshes/Return to Mirkwood in 3017 to coincide with the actual capture of Gollum, that leaves only one year for all the quests to be done before the saga quests start -- which in itself seems highly implausible.)