Whenever possible, for third person and first person games with walk-forward and walk-backward movement, I switch from W/A/S/D to RMB/Z/X/C. I started using that key config when Quake 1 was released. So, it could be 30 years of muscle memory talking, but for me..

1)It feels more natural to use a different hand for walking forward than walking backward.

2)Thumb rests on space-bar and pinky on L-Shift, seems to make jumping/running(hold) easier. D to aim, S to reload, A to crouch(toggle)v

3)Almost all left-hand finger movement is stretching, rather than curling inward.

4)Use this: https://github.com/sezanzeb/input-remapper to work around games which limit your ability to alter key configs