Arm wrestling is all technique. Strength helps but with out the full technique you won't win.
When I was a deck have I mimicked that brocep curl with a cheeta pipe on a ratchet to tighten wires on tow . My arms and shoulders were very strong and could be where my shoulder strength came from .
I did get good at arm wrestling back then but it's because we use to do it all the time. I don't anymore because it leaves me own recover mode for weeks after .
Ben you ever want to work on the river and tow boats let me know. Plenty of iron to lift and food is Awsome