Player vs. Player... I prefer Trouba over Klefbom, for sure, but when you factor in the contracts (or projected contracts), Klefbom becomes more important than acquiring Trouba.
If the Oilers want to keep both McDavid and Draisaitl, they can't afford Trouba. From the sounds of it, if Trouba is playing in Canada after this contract he is going to get paid or sign a very short term contract... in Winnipeg. The Oilers also are not going to give up cost controlled guys, as those are the guys that allow you to keep your core together. How often do teams against the cap (which the Oilers will be for years) trade away their higher end prospects??
The Oilers will have to accept Klefbom and Larsson as their top defensive pairing... which isn't terrible. Neither one is going to be a top 15 dman in the league but they will both be 16-45 ranked D (ceilings), compliment each other very well, are great team guys, Swedes rarely mind playing in Canada (the colder climate cities) and they are on great contracts for the team. We just need to solidify the bottom 4, which I think is very possible with Sekera, Nurse, Benning, Russell and then a few good prospects in Jones, Bear and Paigin.