You're right about being able to wear Ezio's clothes in AC3. However, you are always only able to wear clothes from your ancestors/people who are older than you. It would be weird for Edward Kenway to wear his son's clothes, who at the time of the game either hasn't been born yet, or is still a child. I don't see Edward Kenway running arround, assassinating people while wearing a diaper/toddler's clothes...
You're right about being able to wear Ezio's clothes in AC3. However, you are always only able to wear clothes from your ancestors/people who are older than you. It would be weird for Edward Kenway to wear his son's clothes, who at the time of the game either hasn't been born yet, or is still a child. I don't see Edward Kenway running arround, assassinating people while wearing a diaper/toddler's clothes...