This isn't a fool-proof win plan. I've been in at least two, three games where there weren't enough City States to make a win by the time I got to the other continent with enough money to bribe every one. I had to assemble a continental invasion to liberate them.
Exactly. I am having to maintain a large contigent of Cavs to protect and to liberate captured city-states. Easy to do, though. I do like to focus on science and military, always have been my civ style.