How many bartenders and servers ?

I asked the venue coordinator how many servers and bartenders she was staffing... the # she gave - 3 servers and 1 bartender, plus her as coordinator, seemed low to me... we are inviting 70, expecting 69 maybe... I am mediately expressed concern about one bartender. I could just imagine 50 people waiting in line during the cocktail hour, it would be a disaster and she said she’d look into staffing another bartender. Honestly not sure about how the servers either, we’re doing a plated dinner and probably will only have seven tables plus the head table, is three enough for that? Part of me says yeah they know what they’re doing and part of me says seems pretty low. Curious to see what everybody else is having at their weddings.