There are so many different interpretations to being "tough to play against".
Simmonds is a guy known for combining his skill with his physicality, even though he has not really been able to translate that into production. Bogosian is similar, except he is on defense.
Vesey and Barabanov are actually not guys who will run people through boards all that often, but similarly to Hyman, Moore, and Timashov (although Moore and Timashov did both rack up quite a few hits, even if they were not huge ones due to their size), they are able to leverage their bodies to win puck battles. Winning puck battles is as much about IQ and how to get leverage as it is about strength and size. The Leafs' issue was as much about not having guys who would put in that work as it was not having the size, hence why they added more guys similar to Hyman.