From a guy who loves Matthew Tkachuk, I think Brady is likely going to be the longterm better player. He's more athletic than Matthew.
Both guys are legit 1LW.
Agreed.
The thing is that they both want to play that aggressive, in your face and net-front presence type of game. And both are the most accurate examples of a modern day top line PWF that you can cite.
Thing is though that we can see already that Brady is going to be notably bigger and stronger than Matt is. And not only does he hit more frequently, but he hits harder too. And while its not really saying much, hes a more gifted skater than Matt is. So as far as textbook PWFs go, Brady seems to have a more solid foundation to build from.
Matt is unquestionably more skilled though, and should be good for 5 or 10 more points or so (consistently) each year. His hands are a notch above Bradys. But I would argue that its a smaller gap between them in skill versus the gap there will be in size and strength/physical dominance and hitting ability/intimation factor.
Brady wont be out of his league when Zack Kassian comes knocking at the door and looking to collect for the tab that hes been running up all night. Brady will set the tone and his opponents are just going to have to live with it for the most part, like Chariot did just the other night.
This 6'3 235lb perceived tough guy tried to get cheeky and throw a sucker punch to start the fight Brady (who was unhappy with him high sticking Stuezle twice in the previous game)....Yet Chairot ended up leaving the ice and went to straight to the locker room with what appeared to be a broken and bloody nose after Brady smashed him good.
Matt just doesnt have that imposing size to carry himself like the true heavyweights in the league can. He can be called out, and taken off his (physically). And there is nothing quiet about his confidence either - his bark has a reputation of being louder than his bite (among other things..).
So again hes making a bit less of an impact physically, and putting his teammates in precarious situations at times with his line straddling/crossing antics. While Brady on the other hand actually makes his teammates all stand up a little taller, and even inspires them to play a little bit harder/drags them into the battle with him emotionally. And he will never be accused of avoiding his problems (ie big men that want to hurt him).
Honest answer though, you really cant go wrong with either. Both are incredibly special in their own slightly unique way. The fact that their brothers and came from an NHL legend - who was admired for EXACTLY the same reasons - easily makes the Tkachuks one of the most lovable story lines in the modern day NHL. Even if you love to hate them, its still love.