Just as starting to trade on one pair first is important for a beginner trader, it is also necessary for a new trader to know that the easiest way to become confused is to try to learn different trading strategies from different traders or sources at once.
One trading strategy is enough to make you successful until it is no longer working.
Yes, trading so many assets or pairs can be strenuous and won't guarantee wins. However, trading a single pair won't guarantee wins either. What guarantees wins is how skillful and disciplined a trader is. By skillful and disciplined I meant sicking to one's winning strategy (ies) as the case may be, and trading plan. I don't think any trader solely relies on just one trading strategy but they can flaunt it as they're just one. There's something called "Confluence". That's when traders align two or three of their trading strategies to give them better entries to take trades. That's realistic rather than the idealist way of saying they're trading just one strategy. Whether they're trading MAs and other lagging indicators, Breakouts, ICT or SMC; they always find ways of checking factors that must correspond with their strategy before pressing the trigger.