One token is better because it can be cause some problem to the investors and people who want to support their ICO and project. And one token in ICO is enough for me so that I can focus where or what should I buy. Then I try to look up some 2 token in their ICO project it have bad effect on their project and sale.
Maybe what you say is true it's better to use one token for ico enough so that in the future it doesn't have a bad impact on ongoing sales