I don't think Ryan's problem is that he's too small, but rather (due to his bad back) he's too weak. Someone like Hamblin is smaller, but because his back isn't a brittle twig and he's willing to play like a little ball of hate, it means he's not as easy for opponents to lean on/push around.
Ryan's a guy that gets by with smooth skating, a solid work ethic, veteran savviness/craftiness, and fantastic hockey sense. He definitely has a spot in my bottom 6, as there's reason why he can work well as a 3rd wheel to combos like RNH-Hyman or Foegele-McLeod; but he needs to be on the wing where his lack of strength is less of an issue.
Carrick basically gives you a rich man's Hamblin (that felt weird to type). I do think ANA drowned him a bit defensively (he's not a liability in the slightest, but hardly a shutdown centre. Similar defensively to someone like Shore), but team him up with Janmark and Ryan/Brown to do the actual defensive heavy lifting, and that's a good 4th line with quality defence and a bit of jam.