For me, investing all your savings to 3 cryptocurrencies you have mentioned is not really good idea. Why? because you cannot say what will happen the following days or months if the prices will either go up or down. It is very risky and the rates are flactuating. Also, what if something emergency that might happen in few days or months with your own personal life. Be proactive about uncertainties.
Yes, I like this approach. There is always a reserve option, some of your currencies will rise in price
