I want in on the fun!
I think to have a good rivarly you need something else than two good old Canadian boys. You can have one, but two is just so bland oatmeal starts to sound like an exciting trip down the flavour lane. Btw Matthews counts as Canadian in this instance, because he interviews like one. With Crosby/Oveckin you at least had Oveckin, I don't know what he said in interviews back in the day, but just looking at that face it becomes quickly apparent this is not your traditional hockey "persona". The way he looks at the camera has more personality than all Crosby interviews from his career combined. Yes, I'm exaggerating.
If you want some nice 'rivarly' to discuss endlessly on the forum and an easy narrative for the media to grab, it's obvious Matthews & Laine is your thing. You just have to hope Matthews gets to play a healthy season soon and Laine improves his overall game enough and gets enough ice time to at least be in the discussion beyond his goal scoring only. They might not ever be the two best players in the league (though they still might!) but in terms of made up rivarly, they are already the number one guys.
EDIT: obviously if it's supposed to be two best players in the league and all about statlines and accomplishments, then it gets more complicated, but I don't think those things alone make up for a good "rivarly". It's just not very interesting by itself unless there's some kind of narrative to the thing that goes beyond a statline.