That's about how I see also P13. As far as I am concerned, full-professional level doesn't begin until 5th level (higher for RMSS/FRP/Classic), so beginning at 3rd level is great. (An idea I had recently was to start them at 3rd or 5th, but have "civilian" professions; farmer, smith, miller, etc. and get caught up in a situation that requires them to "step up.")