Well trade yeah, but their big UFA signing on that team is Bozak, who is their 3rd line center.
But here are the home grown Blues...
-Pietrangelo
-Parayko
-Schwartz
-Tarasenko
-Steen
-Barbashev
-Binnington
-Dunn
- Perron kind of, he came back as a UFA but he was originally a blue.
- Thomas
- Blais
- Edmunson
Guys they traded for
- O'Reilly
- Schenn
- Gunnarson
- Bouwmeester
- Bortuzzo (They lost this trade too, Cole is way better than this dope.)
- Sundqvist
- Sanford (who they added in the Shattenkirk trade, which was made while the team was still in playoff position, so this wasn't an "add to win" move.)
Guys they signed
- Bozak
- Maroon
- Perron
The core of that team was very much built through the draft, they then used assets they had accumulated over the years to fill in the gaps with quality bodies where they had holes (down the middle.) The large majority of the guys they added via trade or UFA are middle/bottom pairing D and bottom 6 forwards.
You need to build your foundation through the draft, and history would show that you don't help build that foundation by signing expensive free agents before you know what you have internally (Yes I know, Boston did it but they gambled and got lucky, Minnesota gambled and lost.) I know one little eensy weensy FA signing doesn't seem like it shifts the tide all that much, but it does.