Our open cooking/dining/living area has 3x supply air, exhaust air in utility room/WC/kitchen. On the upper floor, exhaust air in the bathroom and "stairwell" (open), supply air in both children's rooms, bedroom, and dressing room.
A general comparison helps little, as it always depends on the floor plan.
Our house-building company first created a plan for us. According to it, the living area receives 2x supply air and the open kitchen 1x exhaust air. The room is a total of 60m², I don’t know if 2x supply air is sufficient.
It’s the same with us. Room size approx. 50 m²
BUUUUUUT:
The air outlets and inlets each have 2 connection ports. And they are all connected (where necessary). So we basically have 4 supply air ducts in the living/dining room and 2 exhaust air ducts in the kitchen.
I would like to make a note at this point, although slightly off topic: Whenever possible, the largest possible diameter should be chosen for the hose system - usually there are two variants (DN 63/52 or DN 75/63). With a smaller diameter, the likelihood of noise disturbances at the ventilation outlets is increased.