I wouldn't really say it's "all about sacks". It's all about pressuring the quarterback into making hasty/dumb decisions and getting a few sacks per game while you're at it. DTs don't get as many sacks because they can't approach the QB from the blindside (that's also why left defensive ends get more sacks than right defensive ends), but DTs CAN disrupt the pocket and decrease the amount of time the QB has to release the ball. They are also more important that DEs in a run stuffing capacity. Marcus Stround is good at both of those things, but unfortunately none of his line-mates is anywhere close to his level so he draws the double team almost every single time.
That said, I think our talent at DT is better than our talent at DE and that a pass rushing DE is the biggest concern on our D-line.