I will never let go of the crotch wound, but I had another thought.
Houston’s mom had to be a bad-ass to survive what his father put the family through (debt-wise) and then her having to move the family to Tennessee after he died. Houston hooked up with the Cherokees at a young age, at a time when Cherokee women still had a lot of power (even though the structure of Cherokee society had been under a great deal of strain, to put it mildly, and Cherokee women did not have the same status they had even thirty years earlier). And we know his most successful marriage was to a woman who was very strong-willed.
We also know that, whatever happened between Sam and Eliza, as much as it pissed her family and town off, she didn’t seem that angry at him over it. So, what would gravely insult the Allens but not Eliza?
Here’s my hypothesis: Bless his heart, Sam did not know this was an arranged marriage and thought Eliza was marrying him because she loved him. When he found out otherwise, he let her go home, effectively ending the marriage. That’s what he found so humiliating about it that he left. Otherwise, why not just make her stay with him? Who at that time would have really given a shit if his wife didn’t immediately love him if the marriage was an alliance of powerful families? I don’t think it dawned on Houston that Eliza felt she had to marry him for her family’s sake. I don’t think he was intimately familiar with women who would demure to their father’s wishes so it didn’t dawn on him that’s what was going on.
This is my guess, anyway.