this is a good book, to get better results from your EA without there being a super optimization
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Having a look at the numbers the "loss" is still small compared to the gains you would accumulate in the 10 years after. So having a proper money management in mind this whole drawdown period - although it is pretty long I have to admit - does not turn the strategy into a not working one.
That does not mean, that considering a further look into it in terms of further optimization would not make sense, but no matter how large your sample perios is, there will always be an out of sample period, that could lead to different results.