If Prophet Muhammed (PBUH) wanted to annex kingdoms and get women of his choice, this would not have been a problem for him. All his followers respected him and followed him because he showed them the straight path that purified life will lead to heaven where all pleasures are aplenty.
He is not like an ordinary warrior king like Alexander. May be Alexander''s warriors might have been motivated for booty and sex slaves and definitely not Prophet Muhammed (PBUH)and his followers.
MT, again, it is a clear misunderstanding and total ignorance of facts.