this is a Kent thought process
GTAW is all to itself (PAW maybe similar) tell me how wrong I am Lawrence
GTAW run A/C for aluminum and magnesium
DCEN for everything else
SMAW IMHO only done maybe anymore in field work
GMAW, FCAW are how you make $$$$$$$$$$$$$$$
and those 2 run DCEN,
unless your welding foil, then I heard run A/C (never done it)
but those machines cost real $$$$$$$$$$$
same as PAW aka plasma arc welding (never ran a PAW, so no opinion)
sincerely,
Kent