I feel that HN is broken in some fundamental way. The community decides this is worth reading and commenting on, and it gets missed first time round. How many other interesting links get completely ignored and lost.
I worry, I worry ...
What is of more concern to me is that all of the front page articles are genuinely interesting. To me HN does pretty well in this regard. There are so many interesting things out there that it doesn't bother me if some of them slip through the cracks and never reach the HN frontpage.
As long as people don't make an excessively big deal out of "duplicates" and allow for discussion to happen the second time around (or third..or whatever), I don't have a big problem with it. It's an organic process and, as you indicated, timing has a lot to do with it. Many of my posts here get completely ignored -- no votes, neither up nor down, no replies, no indication of any kind it was ever read. Then sometimes a post of mine gets multiple replies and many votes when I figured it would be ignored as usual. I am still trying to get used to that. It is partly the scale of the place. Personally, I find that refreshing. I feel like I have finally found a big enough pond where I can be a little fish and not run into all kinds of nightmarish problems over being seen as too big for my britches.
Peace.