I think those coins that you are holding is already good, And because I've already learned with my 2018 experience when I was bought and hold too many coins and tokens that were resulted in huge losses thats why I'm not recommended to hold a lot of coins, for me just 5 coins would be good enough but in your term, you only mentioned Btc, Eth, PolkaDot, BNB, just make it five add with LINk which is I think another candidate for X10 if the market trend will continue to be bullish.