You're rigth about C3C that ICS/science specialists is enough to get a decent research pace. Reason is the 3 beakers / scientist. Although I think what I will suggest below will also give an improvement in C3C.
But for PTW ICS/SS won't suffice. Of course in PTW also is ICS/SS fine for corrupt cities. But for low corruption cities near the palace and the forbidden palace a working citizen generate's far more science then a scientist, even without a library.
When you, let's say, build rings at 4x and 6x around the capitol and rings at 3x and 5x around the FP. Have the cities grow to (whenever possible) size 12 and build libraries and universities in them. This will give you 30 to 40 cities with an enormous science output. Ofcourse ICSing the same area will create about the same amount of working people, but their cities will be more corrupt.
Only thing you have to do then is timing the completion of the ToE with the beginning of the MT and have a prebuild ready for the Internet.