That will depend on the altcoins because, with so many altcoins on the market, it will not be easy to analyze them, even if that altcoin has a good position in the market. I read the article, and I think Theta, VeChain, BitTorrent, CRO and Harmony can be good as the investment. Still, you need to find out more information about those coins because those coin getting pump for a while, and the coin price now seems not stable and going down again.
I do not know how promising that coin. That is why I suggest you search for more info. But if you are sure that the coins have the potential to increase, you can start to buy now, but remember, do not buy with big funds because that will be too risky for you.