Quoting: sensonfire
1. It takes time for a new player like Henrique to adjust to a new team and a new environment at the highest level of any sport.
2. Broberg and Holloway are both AHL players that need a change of scenery and will turn into busts if you refuse to give them one.
I'd also add that they are both eligible for waivers next season.
Furthermore, Broberg has publicly requested for a trade out of Edmonton months ago.
3. Benning and Kelly on the other hand are established NHL players that would make the Oilers team out of training camp next September.
4. You say, "the only reason to trade either of Broberg or Holloway is for a significant upgrade to the roster".
Alright then ...
So, which of the 31 other teams in the NHL would give you that significant upgrade ?
5. The left side of your defence going forward is Ekholm, Nurse and Kulak.
With that said, if you don't move Broberg, he'll either be sitting in the press box every night or will go on waivers just like Holloway.
1.) Sure, but if he hasn't acclimated more by the end of the season, I wouldn't be comfortable giving him 4*3. Given your scenario assumes they win the Cup, I guess I can grant you the assumption that he meshes by then. However, even if that's the case, I don't think EDM commits that kind of term or money to a player of his age. They're old enough as is.
2.) Sure, they're still AHL players in the same way that any prospect is before they make it. Both are dominant AHL players that are 22 and will undoubtedly receive the very opportunities your scenario assumes they won't get simply because they didn't get it this year. Also, Broberg didn't publicly request a trade. There was a public disagreement between his agent and Holland regarding whether the agent was "given permission to explore trades" (according to Holland, he was not). Likely a tactic by the agent to try to pressure the team into giving him time in the NHL which would, in turn, increase the next contract of both Broberg and his agent.
3.) They're established NHL players that could just as easily fall short of the NHL roster next year (Benning due to injury/age, Kelly because he's a standard 4th line energy W and the churn in that role/position is very high).
4.) At no point did I say there was a team that would give a significant upgrade, merely that that's the only condition I imagine them being traded. That being said, it's not hard to imagine: one of them plus a pick or two for a player of need for the team. For example, Broberg, Ceci, and a 1st for a proper 2RD or Holloway and a 1st or 2nd for a Top-6 W from a team looking to rebuild.
5.) Easy. Trade Kulak because the drop-off from Kulak to Broberg (who played 3LD last season) isn't enough to justify the difference in cap (~1.75mil). Allocate that cap space to filling a more significant hole (2RD or top-6 W).