Are we safe to say investing on both these coins are minimizing the risk
No, with my understanding of trading, investing in two altcoins isn't minimizing the risk, you can research on two altcoins and yet they turn out to be shitcoins. Investing in many altcoins raises the risk of losses because I don't trust altcoins diversification as they are so many and you cannot pick out the one that will be the right one for your investment plans.
Can this site be trusted, do you think a trader can invest based on their predictions?
there are some types of trading and it depends on what we are basing here,if OP wants to be in Daytrading then that is really risky to Buy more than one altcoin but if he can stand for at least semi long term?in which he can afford to hold the coins when suddenly dump after being added to His folio?for me that is tolerable to Buy 2 or more alts for less risk,well this is how i see things because i am not really a trader as i am a Holder and don't want to make way into more risky like DayTrading.