I suspect the shopcrafts were hit hardest, as locomotives
and cars that needed repairs were simply shoved out into
the weeds rather than fix them, as they had too many of
each for the reduced traffic levels. Some shops went from
3 shifts to one and some were simply closed up.

Next would be m/w as gangs were cut off, reduced in size,
etc.

Then field clerical positions.

Back then, as now, it's doubtful that much, if anything,
was cut at HQ.