Considering Evan Bouchard is probably done with Bakersfield and probably at the top of our NHL RD depth chart in short order, I wouldn't bother counting him as a prospect at this point.
Our current LD depth:
Nurse - untouchable
Klefbom - unknown
Russell - bottom pair
Lagesson - waiver eligible
Jones - waiver eligible
Broberg - blue chip
Samorukov - second pair ceiling
Niemelainen - bottom pair ceiling
Cairns - probably goes unsigned
A lot can happen in trades or free agents to shore up that eft side before Broberg even touches the ice in the NHL on a regular basis, so balking at using assets to improve the team now based on some future weakness is extremely overcautious.
This is the kind of logic the team likely followed for some 30 years prior to drafting Klefbom. Lack of ability to add depth from the draft resulted in the Oilers pulling in players from the UFA market to fill depth roles. It resulted in doozies like the Ference, Fayne, Nikitin and Sekera contracts just looking at defensemen.
My point stands. Hopefully the Oilers are going to be picking in the 20-32 slot in the draft for the foreseeable future, which is basically high second rounder territory. So the odds are the players who will fill the future depth spots have already been selected or will be traded for players who can. I haven't seen anything on Broberg to make him untouchable.
Fortunately this team is playoff calibre without the 'help' in all likelihood. So making permanent long-term decisions in a weak FA market and from poor trade position might be a bad strategy.
You'll always be in a "poor trade position" if you refuse to give up any actual pieces of value.