The indoor space is more important to consider than the run space- especially if you let them out for a little free range. To make a crowded run more livable, add perch space and entertainment. Hanging cabbage or other greens for them to peck is usually a winner. It keeps them from pecking each other.
I wouldn't want to go over 2 dozen. for your setup. It's always better to have more room.
I wouldn't want to go over 2 dozen. for your setup. It's always better to have more room.