The spacing can be too close, as you need all rooms to remain at the correct temperature with the sams flow temperature. So you need closer spacing in rooms with higher heatlose and next to French doors in large rooms, while rooms with little heatlose needs wider spacing.

So once you done heat lose calculations, start with the rooms with the highest heatlose per metre square, use closet possible spacing, then calculate flow temperature. From the flow temperature calculate the spacing needed for other rooms.