Flash white balance varies with flash power level (depending on power range, typically at least 200K, more likely 400K to 1/32 power, from high to low power, and is the probable intended meaning of your spec). There is no one value of flash white balance, not even in one flash unit.
Speedlights typically do not even specify white balance, because it varies with power level (studio lights vary with power level too, but they typically mention one at full power level). Some users are agast when they discover this variation, imagining a defective flash, but it is of course just a simple fact of physics. Just how life is.
Flash is generally near Daylight white balance, but it varies with power level.
Speedlights become more blue at low power, and most studio lights become more red (but a few can operate like speedlights).
Speedlight low power is a short duration that chops off the weak trailing red tail, and voltage controlled studio lights simply become a less powerful (warmer color, red vs. blue hot) flash. Some studio lights claim +/- 50K, just meaning the one Full power stability. You know how marketing is. My site has a sample of that speedlight color change: https://www.scantips.com/lights/whitebalance2.html#pwrlvl
It is not necessarily a problem if we correct it. Using two flashes for a portrait are surely in a main/fill relationship (main close and at around 45 degrees, with a frontal fill), at different power levels and different distances. But the subject is dominated by the close main light. Correcting with a test shot with white balance card at the subjects location and light works very well.
Here's a good article about working with flash white balance by a manufacturer.