Airport ATC is easy because you don’t deal with lost transmissions as aircraft can’t move onto the next phase without acknowledging save for the aircraft that take off before getting cleared too. Airborne ATC is the real issue to deal with. More than 3 transmissions and you’ll never hear readbacks. Which is why I only listen to airport ATC because I can actually follow what’s happening. Even then since every freq can be used for each aspect such as clearance, ground, tower, it makes it very hard to follow everything that is going on. FSX had it right. No more than two towers based on the position of the runway for the airport, same for ground and one clearance.