Interesting claim.

  ELLSWORTH (CONT'D)
  I tell you what -- I may have fucked
  ~~ life up flatter"n hammered shit,
  but I stand before you today
  beholden to no human cocksucker
  and working a paying fucking gold
  claim -- and not the U.S. Government
  saying I'm trespassing or the savage
  fucking Red Man himself or any of
  these other limber-dick cocksuckers
  passing themselves off as
  prospectors had better try to stop
  me.

I can’t hear it, although it certainly has certain rhythm to it (like any good dialogue does). Iambic rhythm however is so typical to English that you can kinda force most dialogue into it? I also believe writers make these rules to brake them the first change they get. Or perhaps I couldn’t find it skimming the pilot script: https://assets.scriptslug.com/live/pdf/scripts/deadwood-101-...