In my opinion, diversification of the funds is a good idea on the cryptocurrency market and I am using it as well, but currently it might be better to hold only Bitcoin and stablecoins as they are the strongest coins during the current market conditions.
Of course it is a great idea.
No matter how confident you are in a project, everything can fall apart due to a bad actor. Look at how faketoshi destroyed both BTC and BCH in terms of price.
You can never be 100% sure of a project success, unless you're personally involved.