Dwarves and Mordor

[Kuruharan]

On a bit of a tangent, any speculation as to what houses (or parts of them)
of the dwarves fought on the side of Sauron in the battle of the Last Alliance of men and elves, and why?

If we go by the assumption that Tolkien listed his dwarves going west to east the Ironfists and Stiffbeards would have been closest to Mordor. The Blacklocks and Stonefoots were farther away.

Only the loosest of speculation is possible here.

Why they might have fallen into evil: Lack of an alternative. If you stop and think about it, there is a strong possibility that the dwarves were the only civilization(s) with a cultural basis for resisting Sauron. The tribes and nations of Men in the east tended to be those who had fallen under Morgoth's sway way back in the bad old days and stuck around. The elves were gone. Basically the dwarves seem to have been it. Cultural interaction will have its impact, and I doubt that the dwarves stayed away in the mountains and had no contact with others. Since the Ironfists and Stiffbeards were closer they might have had more contact with people under Sauron's sway. However, this is a wobbly supposition at best.

However, this is a very gray area because these Houses fought in the War of the Dwarves and Orcs against the orcs. But on the other hand, "bad dwarves" are spoken of as having made alliances with orcs. This obviously did not refer to the Longbeards nor to the Firebeards or Broadbeams. This may have something to do with Tolkien's earlier conceptions of the dwarves.

Hmmm...idea forming in brain...perhaps the dwarves in the eastern houses developed a mentality similar to that of Mim. Basically out for themselves more than anything else and willing to work for whoever offered them a better deal. Sauron offered some of them a better deal and they took him up on it.

A real reach here, and done completely without access to source material, but by chance were the "swarthy men" who participated in the Siege of Minas Tirith (think that they had axes) a cross between between men and dwarves? Saruman was doing this with the orcs and men, and so would Sauron do something to produce a race of more controllable dwarves?

It is hard to deny that this is possible.