Who is more evil, Daw Jackson or Pierce?

A strong case could be made that Daw Jackson is more evil than Pierce.

As far as we know, at the beginning of the movie Pierce is only guilty of one attempted murder (Daw Jackson), one murder (whoever Jackson was framed for murdering) and various counts of conspiracy, fraud, obstructing justice, etc., etc.,

Some of Pierce's gunmen discuss murdering Daw Jackson, but he has many more who are not in those scenes. It is quite possible that many of Pierce's guards are honest men who think that they are working guarding gold shipments and nothing more.

For greed and for revenge - and doing something for the evil purpose of revenge makes it even more evil than it would otherwise be - Daw Jackson started a gun battle in which he could expect that a number of persons would be killed. A person who commits a crime like robbery is guilty of murdering all the people who die violently during that crime.

What is the vilest of crimes that the most evil villains in many old westerns do? Starting an Indian war for the purpose of financial gain. For example, Van Ellyn and his repeating rifle manufacturers in the Plainsman (1936), Gillespie in Geronimo (1939), Cliff Taggert and Ben Alsop in Indian Uprising (1952), Crawford Owens in Apache Rifles (1964) etc., etc.

Daw Jackson, for reasons of financial gain, got a Kiowa band involved in a robbery and shootout, thus risking starting a war with the Kiowas, in which tens or hundreds of people, including women and children, could be killed.