was Harv Pell the ........

Nah! He was on the marshal's side. The problem with Harve is that he felt they'd be outgunned by the Miller guys, and with (likely) no one jumping in to given them aid. The church scene showed that Harve's thinking was right (for Harve). If that one guy who'd been on board, then changed his mind (Herb?) for his wife and family, had hung in, the three men would have had a chance; and also, others might have joined in out of respect (and affection) for the marshal. Will Kane won anyway, with some help from his loyal wife, but the town folk never did rally. They showed up after the gunfight, when the fight was over. That was a sad and bitter ending. The marshal throwing his badge in the dust struck me as the right thing for him to have done. He felt that was what the town deserved; and I'm inclined to agree.

I am going with Mayor Henderson and his contemptible speech in the church that the town’s prosperity depended on betraying Will.