I don’t think last year’s playoff series or 2013’s playoff series means all that much for how Toronto would fare against Boston.
The only players from the 2013 roster still playing for Toronto are Kadri and Gardiner. That should tell you pretty quickly why that series is totally irrelevant to what would happen between them today.
The 2018 playoff series is obviously far more relevant but I don’t think it means that Boston “has their number”. Boston was a very strong team that finished 4th in the NHL with 112 points and 2nd with 47 ROWs, while Toronto finished 6th with 105 points and 9th with 42 ROWs. The reality is that last season, Boston was just a little bit better, in what was a weird series where Matthews was injured and Kadri got suspended. And it still ended up being a 7 game series where Toronto held a lead going into the 3rd period.
This season, Toronto is 2nd in points percentage and 2nd in ROW, while Boston is 9th in points percentage and 8th in ROW. I think Toronto is the better team so I voted them.