However, in the long run, having multiple investments won’t make you real rich if you aren’t capable of managing them well. It’s easy to invest one at a time, start with a small amount and challenge yourself to make it grow and progress through your knowledge, skills and perseverance on your investment.
Having multiple investments would be ideal as long as you pick them carefully. You wouldn't want to invest in many assets for all of those to end up being invaluable or a failure. You can pick only a few ones as long as they are incredibly good and profitable.
The diversification is the way to go, there isn't anything that can be improved that way. We need to see that sometimes diversification comes at a cost. Because if you have 5 assets you invest into, and 4 of them are good, and one of them is bad, then that means you could have used that money to buy more of those other four. That means, you need to be careful when you are investing and making mistakes would cause you a lot of trouble and no need for anything better.
Focus on good ones, and do not force diversification, if you can find good ones then yeah you are going to be fine, but if you are not good enough then I am not sure what to do, there isn't really a reason to diversify if you can't find good reasons.