The average team / staff have full time at ICO should have a total of 30 people consisting of: marketing specialists, designers, programmers, promotional specialists, content managers, lawyers, technical directors, public relations specialists, etc.
I understand where you are coming from and it is very typical with ICO's now but I think it is being done for marketing only. I actually think this is a problem with ICO's as many teams are now bloated with members who do not actually contribute anything other than putting their name on the ICO website and once the funds are raised they are on to the next ICO.
Just my opinion but if you have a 30 person team you should be well past the ICO phase of raising development capital; at that point you should be raising expansion or operating capital (if needed). Most startups grow from a team of 5, from Business Insider study - "general rule of thumb for the optimal headcounts at each stage of a developing business five employees for startups in the building product stage, 10 for companies in the building usage stage, and 25 for the building the business stage". If you look at the some of the most successful companies; Microsoft, Google, Facebook, Airbnb, etc. you will find they all started very small (usually 1 person with an idea). Ethereum was one guys idea but even the core Ethereum team was Vitalik Buterin, Mihai Alisie, Anthony Di Iorio, and Charles Hoskinson. Even Bitcoin could be one guy (or gal!) but I'll let you know when I find them