Ok now before you cut my tongue out and burn me at the stake and proclaim me a heretic, hear me out first. I have read the FAQ and the things not to post however I believe this particular matter has not been covered. It is written in the return of the king and the lord of the rings ( which one I do not know ) in appendix A in section III Durins Folk that Moria was reclaimed by Durin VII. Now it's time for a little back story. In the Years of THe Trees, when Durin first awoke his reign was so long and unforgetfull he was named The Deathless. Now lets fast forward to The events in the Hobbit. At the end of The battle of the Five Armies, his return was prophecized. Durin was supposed to return a total of 6 times, with Durin the Seventh being the last of the line, thus ending the Dwarvish race. In the Second year of the fourth age, he was born as the son of Thorin III Stonehelm, son of Dain II Ironfoot. It is said that later on during his reign, he retook Moria and refounded the Kingdom of Durin and retook the Crown. That being said, I am not saying to add the Dwarves of Moria but rather reconsider them. They don't have to be the dwarves of Moria, they are as a matter of fact part of Durin's Folk.
If you've read the paragraph above, you don't have to read the remainder of this post; the following are wild fantasies of mine regarding this mod. Now, the dwarves of Moria cannot simply be added at the beginning of the game, as that would be unforgivingly uncanon. However, what the developers could do would be create a major questline regarding the mines of Moria. For example, it would start with the death of Thorin III Stonehelm and the player would be invited to their funeral. At the funeral they would meet his son Durin the Last who would ask the player to rejoin him at the Lonely Mountain afterwards. Once the player would meet Durin, the latter would ask him to join his company to retake Khazad-Dum thus setting in motion the questline.
Well thats all for this post, tell me what you think in the comments.