I agree with your main point, but St. Louis is not a good example. Best team in the league the second half of the season.
They're a good example of a team that's been considered to be in the same purgatory that the Wild are: good but not great, can't get past the 2nd round, need to blow it up, etc.
Then you look at who led them to that cup...
O'Reilly - 2nd round pick, traded for
Binnington - 3rd round pick
Pietrangelo - #4 overall
Tarasenko - #16 overall
Schwartz - #14 overall
Schenn - #5 overall, traded for
Bouwmeester - #3 overall (a million years ago), traded for
Parayko - 3rd round pick
And the next wave of young guys they have coming...
Dunn - 2nd round pick
Fabbri - #21 overall
Thomas - #20 overall
Blais - 6th round pick
Kyrou - 2nd round pick
Pietrangelo's basically the only guy the Blues themselves drafted in the top-10 and that was 11 years ago. The rest of that roster was put together with trades, mid-to-late 1sts or later picks, and UFAs. It's exactly the approach that HFBoards seems to think cannot win a cup.