More frequent attention is a solved problem: a server walks around with a tray of filled glasses and always replaces empty glasses, except if they are covered. That way, the communication overhead is reduced, and a roundtrip per table back to the bar is no longer required. With that, the number of servers can also be kept to an efficient minimum.
Obviously, this works only if a very small selection of beverages are served.
Obviously, this works only if a very small selection of beverages are served.