I couldn't help but laugh when I read this tweet, Stroman is obviously trying to be optimistic about his comrades and his own ability, but he took it a lot of bit too far. Blue Jays have a solid starting rotation, no doubt about that, J.A. Happ, Aaron Sanchez, Marcus Stroman, Marco Estrada, and Fransico Liriano are certainly a top 10 starting rotation in baseball. To call them #1, though, that's absolutely ludicrous.
J.A. Happ posted an appetizing 20-4 record last season, which is nice and dandy until you realize he received almost 7 runs per game in run support. He had a solid 3.18 ERA, but he's no ace by any definition of the word. Aaron Sanchez is an up and coming stud, he went 15-2 posting a 3.00 ERA, however like Happ he received a healthy amount of run support at 5.63 runs per game. Sanchez is the Jays best chance of getting the ace they need, but we need to see if he can build off his 2016 season before we start jumping to conclusions. Marco Estrada went 9-9 with a 3.48 ERA, he was definitely a better pitcher than his record showed, but still not close to ace status. Marcus Stroman, a very solid young pitcher, a fan favorite, and the man that made the comments saying his team's pitching staff was the best in baseball, was arguably the worst pitcher on his staff last year besides for Fransico Liriano. So no, the Blue Jays are not even close to the best in baseball when it comes to starting pitching. They do have a lot of potential this upcoming year, however they're not quite there when it comes to being an elite pitching staff.
The Red Sox, Mets, Cubs, and Indians have elite pitching staffs they all have numerous aces while the Blue Jays have none. The Blue Jays have 5 quality starters, yet they have no aces. The Mets have 3 aces when healthy, and two starters that could potentially be aces down the road. The Red Sox are in the same boat as the Mets in regards to their pitching staff. The Cubs have 3 aces, they don't quite have the depth as these other clubs, but their three aces make up for the lack of talent at the back end of their rotation. If the Indians rotation can stay healthy all season, which they never seem to be able to do, they can be just as good as anyone in terms of starting pitching. I'm sure there can be cases made for a few other teams, but you get the point, the Blue Jays are clearly not even close to being the best pitching staff in baseball.