Listing a goalie as an example of chasing size is disingenuous. Obviously that's not what we're talking about here in this discussion. As for their defense, Garrison has 34 hits in 50 some games, Sustr has 31, Hedman has 38, Stralman is known as a puck possession/puck mover, etc. For reference Letang (who isn't perceived as a tough guy) has over 100. So I guess if you really want to you can point to the big D men as Tampa going after size but these guys aren't exactly Doug Murrays out there. They all really are good at moving the puck, puck possession and their size isn't really used for physicality except as an afterthought.
Besides I was really talking about their forwards Johnson, Palat, Kucherov, Namestikinov, Drouin, etc that are all slight of build with tons of skill. It speaks to a concerted effort to draft based on ability and size comes in only as a secondary consideration. These guys are killing it now.
Size does matter. It just matters way less than most people seem to think.