Thinking about it, if I had ten sex slaves to indulge my fantasies on, I think I would be searching for that elusive eleventh, then twelfth or probably just concentrate on the one who intellectually stimulated me the most.
Sultans who could potentially have scores of wives and often did, tended to have one or two favourites. The politicing between the concubines for favour could also prove something of a headache.
Nice fantasy but potentially a nightmare.