The other way to approach this is, take the bet that Pearson will be an ace. Jays have plenty of back end options. With this bet, the need is #2, #3 starters.
No need for taking on the risk, $$$, and term associated with a Cole.
It's making a bet, but not a bad bet to make in the Jays situation. No guarantees in baseball, either that Cole will be an ace when the Jays need him to be one, or that Pearson will develop to a front line starter.
Also noting the 1st two years of a Cole contract likely wasted.