I think bitcoin and ethereum are good to go but rest of the coins mentioned here are also good but you have to go with more risk. From here I would suggest you to go with Solana, $ADA, $Doge, $Link if you can go with more risk. I think all these coins must generate new ATH in the last five years. If I had $40k to invest I would definitely invest 80% in Bitcoin and Ethereum and the other 20% I would invest in all these coins and move on.
If someone choose a single coin but top coin then there is a greater chances of success and risk will be minimum but if someone diversify their investment then he can sell anyone of desire coin to take benefit when he needs money. Altcoins can be selected for short term but bitcoin should be kept longer until Bull season arrives.
Your percentage of investment in Bitcoin, Ethereum and other altcoins are a wise step and I think everyone should divide their capital for investment in such percentage. We can use larger percentage for bitcoin and Ethereum without fear of losing money but if such higher percentage is putted into altcoins then we will be in fear of losing money until Bull season originates.