Spoilers - I just finished avatar 2, and I'll say, the biggest problem with the earth forces (that lost) is that they had no diversity other than the single smart Jewish scientist, and the Asian who harpooned the whale like creature. Not a single black, Indian, Mexican, Arab, or other person of color fought against the blue and green spear chucking people. All those super toxic white men and women invading paradise and needlessly killing every creature and degrading every other person they see really caused it If they just had diversity, they would have won.