I wouldn't be opposed to trying DeAngelo on the left as he has played there before, but I would be really hesitant to pair him with Trouba. I think Trouba needs a more "safe" partner. Morrissey, who Trouba excelled with, is a great skater and really good moving the puck both by transporting it and passing it. But, he's also really reliable in his own end. He is more of a traditional two-way defenseman whereas DeAngelo is your more prototypical offensive defenseman. Trouba needs to be paired with someone that doesn't take a lot of risks and can be counted on to make smart plays, which allows Trouba to roam around a bit more, open up his physical game, and get involved up front.
The Skjei-Trouba pairing sucked because Brady is a moron who was always doing idiotic things both on and off the puck, and Trouba was too much of a gambler himself to cover for Skjei's mistakes (and Brady as incapable of covering for Trouba). To make the most of Trouba you need to find him another Morrissey. That is NOT DeAngelo. Even an Anton Stralman-type would be great next to Trouba.