^^Well, judging from the scale marks on the planar view, the separations between the major stars are typically on the order of 40-50 AU, which is the distance from the Sun to Neptune or the Oort Cloud. From that distance, a Sunlike star would be just a bright point source, not enough to brighten a night sky significantly or be visible in the daytime sky of a planet lit by a nearer star. The minor suns are apparently red or brown dwarfs, which would only cast daytime illumination if you were much, much closer than 1 AU. So the system layout shown here is compatible with only seeing one sun in the sky of any given world.