Questions about Heating/Cooling, ducting
If it works to your satisfaction (that is, if it heats the house properly), then leave it alone. There are a LOT of factors in this, including:
length of individual duct runs
openings between rooms (door or no door, closed or open if door)
sizes of rooms
placement of vents in the rooms
placement of the return vents

I'm no HVAC guy, but I know enough to know that if it's working, DON'T mess with it further.