If you won, say, 5 wars (which - yes - will put you in a small minority, because some countries had to be losing these wars, and obviously the losers outnumber you), then you can afford losing another 2.

But if you only ever lost 1 or 2 wars, you're no longer on the world map.

I think it's fair to say that, however you look at it, the quote is using "hard times" and "good times" from the perspective of the in-group, not any out-group. So, whatever destruction Alexander visited on those he conquered is kind of irrelevant to this quote - the only thing that would matter for checking whether the quote applies is whether Alexander improved the lot of his own people. That is, was he a strong man who was created by the hard times of his youth/parents' generation, and did he create good times for his own people?

Per the quote, the people Alexander conquered should themselves be considered weak men who will leave hard times for their children (being conquered/looted by Alexander, who they couldn't win against because of their weakness); but whose children, or grandchildren, will be stronger than them and create good times anew.