First they pick a battery chemistry they are going to use in flashlight then consider about brightness, run time, bulb life and flashlight size.
Example: If you are using two cells of primary CR123 and brightness of about 60~80 lumens, and run time of minimum an hour which shouldn't be more than 1.2A Amp, bulb life shouldn't be more than 40~50 hours and flashlight size can't be smaller than 4.5"
That is interesting, but the only reason I was trying to figure out what lights there are and what their cells' voltages were was to determine if their lamps could be used in what Li-ion cell configurations. Just because a Streamlight uses a 3.6V NiCad to drive a 1.6A bipin doesn't mean it won't

on a single Li-ion, nor that a Streamlight that has a weird long 6V NiMH replacement cell doesn't mean the lamp it drives won't

on 2xCR123A. And I wouldn't care so much, but the lamps aren't exactly cheap, $8-$12/pc.
How many different Streamlight bipin xenon lamps are there? How many can be driven with IMR/INR or LFE or CR123A without throwing money away flashing lamps? I have only seen you suggest two different Streamlight lamps before, Strion and Stinger, and today, now Scorpion. That's actually a pretty good start, so, well done, thanks.