I often get requests for females only and I'll ask why. Many of the responses fall into the "sugar and spice and everything nice" expectations ... not with corgi girls.
That's not saying I don't have sweet girls, the boys are just more biddable. In talking with Breeders more often than not when asked if they could only keep one of their dogs, which one would it be, the majority of them say they would choose one of their boys. There is just a level of sweetness and loyalty they don't see in their girls.
The marking, humping (shoot I've got girls that are as bad about that as the boys), training and neutering solve 98% at least of those type problems. House training - I haven't found one sex to be more difficult than the other in that area. I've had boys that caught on very quickly and girls that took forever and vice versa.
Debbie