I use a knife, boys I hunt with would laugh their asses off if someone brought out woodworking tools.
How bout a sazall or a chainsaw?
A small hatchet splits the pelvis on older deer a hell of a lot easier than a knife.
The pelvis on small immature deer is about as soft as butter and is easily spilt with a knife.
I did split the pelvis on my buck w my fixed blade this year but broke a fixed blade Pachmayr on my buck 2 or 3 years ago.
I prefer to use a hatchet for the pelvis and use it some to remove the head when I am done skinning.
Now break a chainsaw or sawzall out of your pack when field dressing and that's when the laughing would start.