Hal,
No way there were two. What Hermann didn't have back then was the internet, city records online, ancestry.com, ISTG, and several other places where we can follow Jacob Waltz. The name is spelled Waltz on his Citizenship Papers, census in Los Angeles, his participation in the Weaver/Peeple's Party, his records in Phoenix, the newspaper article about his death (I am pretty sure Julia would have made sure they got his name right), and several other places I can't name off the top of my head (don't forget his tombstone). Can you show me any any such trail through the same areas for a Jacob Walzer? We have it all from Jacob Waltz, but no Walzer.
I don't know if you can access ancestry.com, but I can. When I look for Jacob Walzer, I get a guy that came over from LaHavre to New York in 1860, and lived his life in the Northeast. NO Walzer on ANY records on Arizona. Same thing for Walz (Ft Leavenworth, KS, and Missouri). Nothing in Arizona. Waltz (on the other hand) is chock full of records.
Mike