True & Honest Fan
Turtledove is a professor of Byzantine history by training, and it really shows in his work. Anything he writes that isn't (loosely) based on Belisarius and Justinian kind of misses the mark. But both he and Stirling are guilty of adding excessively gratuitous sex scenes into their alternate history novels, making many of them nigh unreadable to me. If I wanted gratuitous sex scenes that don't detract from the main plot, I would read some of the more graphic titles of French uchronie.
I can't speak for Stirling based on the few chapters I read of his online, but yeah, even those few chapters had IIRC a rape, and lots of mention of rape. Turtledove does shoehorn in sex scenes, but IMO they aren't distracting from the plot. I can even understand why he does them. He writes books about war, but he also focuses on the human aspect of it. He writes about adult men and women and because of this he feels it necessary to squeeze in a couple sex scenes. Thankfully, they're typically short and to the point, but I agree, they are unnecessary.
That's the one I read a few chapters of online. Super South Africa with lots of rape.