You can check about their team. whether it's on Twitter, linkedin or other related social media.
If you want more information, you can visit ICO observer sites, such as Icobench and others.
Correct name is ICO rating sites and they should be used to discover new ICO's but not as investment advisors.
it is hard to detect now, since scammers are getting wiser and innovative by using well known names and creating false publicity. Everyone should be aware of unrealistic goals of ICOs.
I don't know why is hard. It is your money. Talk to people face to face. You will be sure if name is only used or is real.