Well from what i have read ducks need a minimum of 4 square feet of coop space for night time. 
So sounds like your coop is pretty tight... 'maybe' 3 would work. But unless you plan on making it bigger i think 4 may be pushing it a bit....
And 10 square feet per duck for the run. So you have enough run space.
Maybe someone else has more advice on the size of the coop.
I have never tried to house mine in that small of an area.
If you cant add on to the coop maybe its best to just keep the 2 together for now.
	
		
			
		
		
	
				
			So sounds like your coop is pretty tight... 'maybe' 3 would work. But unless you plan on making it bigger i think 4 may be pushing it a bit....
And 10 square feet per duck for the run. So you have enough run space.
Maybe someone else has more advice on the size of the coop.
I have never tried to house mine in that small of an area.
If you cant add on to the coop maybe its best to just keep the 2 together for now.
	
