I play a wide variety of basses with different scale lengths and number of strings. They are all setup with nearly identical action, which to me is the critical factor in feel. I rotate through the different basses when I practice, so I'm familiar with each. When it's time for a gig I chose a bass based on my mood and/or the music I'm playing (sometimes the location, i.e. a single coil P bass is not a good choice for a room that has questionable grounding or noisy wiring). To me variety is the spice of life, why limit yourself needlessly.
My advice make sure your P & Jazz have very similar action, then use them both until you feel at home on either. YMMV
My advice make sure your P & Jazz have very similar action, then use them both until you feel at home on either. YMMV