I like Reilly Smith 3 years ago. I'm sure he'll fit in, but I would've rather spent that cap space elsewhere when we have 2 young 1st round picks that need to play up there to either show they can/can't do it in Kakko's case or to develop in Othmann's case.
I think it makes sense when you consider how deadline acquisitions for that spot haven't been good either. They'll potentially give up a lot at the deadline for very little proven chemistry, even if it's a big name like Kane or Tarasenko.
With Smith, you at least give that line the ability to build some chemistry through a camp at few dozen games in the beginning of the season before you need to consider changes. At a low cap hit, that could be a smart move. You could always swap him with another player later on if it doesn't work out.
But that line needs to produce at even strength during the regular season if they are going to make any actual noise in the playoffs. If Zib and Kreider are ever going to be productive 5v5 again, especially in a deep round of the playoffs, it's not going to be because the rotating cast on RW suddenly clicks with a new player in March.
Neither Othman or Kakko have shown they're the guys yet, and this core has a win-now mentality for this year before they start selling off guys.
But I don't see it as a bad thing to have some depth on RW and force one of those two to earn a top 6 role or be a backup in case Laf or Smith get injured.
Having some flexibility to figure things out on RW in October is a hell of a lot better than not having any flexibility in March and needing to spend to acquire depth.
TLDR - They got Smith because they need depth on RW and didn't have it until now.