you cant force them to sleep. just see wat u think works. if he is sleeping through the night then that is great. if u try to push him to sleep more through the day he might not sleep as much at night. my nephew is 4 months and he has 1 to 2hr sleeps but it is only like 2 times a day and of a night he wakes constantly.
If he "needed" more sleep then he would be sleeping longer.