Roden, Wagner, and Santander have a combined WAR of -1.2. They essentially replaced Roden and Wagner with Varsho and Barger in May, and have gone 10-2 since Tony's been on the IL. You replace really bad players (or players performing badly) with good ones, and that can help explain a difference in RD, especially when mixed with Kirk's resurgence and other internal improvement. I don't know if it's sustainable as is, mostly because 3 SP's and 2 bullpen games a week is going to heavily tax the pen and they can't get away with it for much longer, but the Jays I would imagine will be one of the more aggressive teams at the deadline, so external pieces are probably on the way. It's just a matter of how long they can keep this going until that happens. Scherzer replacing Francis is super important. I don't trust Max's health, but we just have to hope. Then add a SP at the deadline.
Honestly, I don't know what to make of this team right now. Exceeding my expectations, and I'm enjoying the ride from May onwards.