In terms of physical strength... sure, one can compare a weak horse to a strong horse in the same way one can compare a weak man to a strong man. Strength is an advantage, weakness isn't. A strong lion will bring down a wildebeest more often than a weak lion.
Considering your clarification...
By weakness I mean the common usage, making the wrong decisions, failing at things, self-destructive behaviour, depression, anxiety, being a nerd, a loser, a freak, and so forth - even disposition towards actions such as being overly generous, trusting, or gullible. — kudos
strength and weakness are not as clearly differentiable among we humans. Is being a computer nerd a strength or a weakness? The handsome, healthy, hot athlete may get to mate more often, but if what is needed at the time is insight into printed circuitry and code, how useful will the hunk be? Fun to fuck but after that... pffft.
There have been a number of discussions here about the evolutionary value of depression. What good is it? Not sure myself, but some people think that "depression" has value to the group because anxious depressed people are sensitive to potentially dangerous situations that the hale and hearty are not. Personally, I haven't found depression to be an advantage, though it might lead to insights that a mentally robust person wouldn't arrive at. And not all insights are equally useful or healthy. Sometimes it is better to not look behind the curtain.
Loners, Freaks, losers, nerds, et al living outside convention as they do a good share of the time, can bring fresh perspectives to the community. Some of our great inventors, authors, artists, musicians, etc. were loners, losers, freaks, nerds, and worse--if you can imagine anything worse. (Most of the greats were more or less socially successful, but not all of them were.)
So, among human society, weakness and strength are not as obvious as they are among animals. Sometimes strength comes from being an alienated, dysfunctional outsider. An outsider will probably have better vision to see society as only an outsider can.
Take Thorsten Veblen, a late 19th century, early 20th century economist and sociologist. Some of his outsider traits enabled him to see the purpose of large, carefully tended lawns: They are conspicuous consumption -- proof that one has a lot of money to maintain a perfectly useless field of grass on which no sheep or cow will ever graze. It is difficult to get such insights into society from the perspective of a socially successful person. To the wealthy-enough homeowner, the large lawn is inherently justifiable, and worth all the work that goes into it.
A weed patch in front of the house, on the other hand, is proof of one's failure in society. Success = nice grass; failure = weeds. I have weeds in my lawn. I agree with Veblen: large chemically dosed lawns are bullshit and ought to be stamped out. Screw the middle class lawn mower.