Bob,
You are correct and if more then 3 people were playing at one time the dealers HAD to watch closely and keep track of ALL of the various bets that may have been placed at one time. I am sure that the extra help needed to run the French Style Table was one of the reasons the table was taken out of play. If I remember correctly there were four dealers/pit bosses watching the French Roulette table while it was in operation.
"Mr. Roulette"
P.S. See the scan below for pictures of other Paris $20 and $50 Jetons.