A very wise policy.
You can invest in bitcoin.

Or you can gamble (read throw your money up in the air) with DOGE, Digibyte, Shiba (at least bet on horses that are still alive)

Or you can... not sure of a good word, put your money where your mouth is? With HIVE, Theta, LTC.

But none of that is really diversifying.
Diversifying is when you have something that will do well when everything else goes to crap.
Such as, buying some PMs. If cryptos don't make it, you will want all the gold and silver you can get.

Buying stocks and bonds is not diversifying. They both go up in the same fire ball.

Overall, i agree with you. Any recommendations, unless you really, really know crypto, is bitcoin. But bitcoin until you are sure of real moves in the market. Like, in 5 years, bitcoin becomes a savings account, and litecoin is the spending money. That time will be obvious.