I dont like ICS, i think its much better a few very good city and increase city size, a city on a river with 2 luxuries a temple and 10-20 % lux will reach size 12 into republic, producing about 20 shield a turn and several beaker if you got library, i am able to to take a lead in science on regent level easily and when you can crank up knight in 3-4 turn no tiny little city size 2 will survive.
ICS is an extrem settler diarhea done by human, i prefer much much more 15-20 very good city.