15 books a year?

There's a fuss in the fuss-prone world over "M/M Romance", where gay fiction is the domain, mostly, of straight women writers (you'd have thought Mike Huckabee would have issued a fatwah on this by now).

Anyway, a writer called Laura Harner stands accused of plagiarizing straight romance novels to prop up her torrid rate of publishing fifteen books a year- 75 in the last five.

Some argue that it simply can't be done- you can't publish that many, that fast, even with wide margins, short chapters, and shorter words. 

I was curious, if only slightly. The famed romance novelist Barbara Cartland (1900-1998) was renowned for her publishing prodigality. In a 75 year career, she published 723 books, and left another 160 for posterity. And even that averages to only 59 books in five years. Mind, I'm not curious enough to count five year periods in her bibliography to see if she managed a grand slam here and there. But it seems like 15 a year is a squint. 

What do you think?