I live in one of those countries where men take long periods of paternity leave. You're not suppose to overlap it except at the very beginning 🤦♀️What on earth would be the point in that?
Fathers take a couple of weeks after the birth to support mother and newborn in the immediate postpartum recovery period. Then they go back to work. Then when the mother goes back to work, the father goes on proper paternity leave.
This is a system with huge benefits. It stops mothers becoming the default parents as fathers need to learn to do it solo. They have that experience of being the main caregiver. Of course it's not exactly the same as it is frankly easier to look after a weaned 8 month old with an established nap schedule than it is to look after a chaotic newborn, but it helps A LOT.
It's brilliant for babies and fathers - and mothers too.