In a studio where you are in total control of the lighting there should never be anything blown that you didn't want to be blown, and vice versa, a histogram might tells you something is blown/blocked up but not where, so its of limited use. A flashmeter will sort the exposure and lighting ratios for you added to knowledge & experience. One of my best mates is a great studio/portrait Pro and trainer and I can't recall him ever bothering with the histogram either. I've also attended studio days with some of the UK's best and neither of them mentioned histograms at all
Don't confuse "Pro' with someone knowing what they are talking about or meaning they are right - I'm a long term Pro too and I could also be talking gonads
Looks like the OP's question has been answered fully now, if not that clearly as there's obviously several ways of working, all that matters is the result not the way you get the result
So - I'm out
Dave