The Nats traded Robert Garcia for Nathaniel Lowe from the Rangers. It's a solid, if unspectacular move that makes the Nats better, without giving up too much or costing them a lot of money leaving them the ability to do other things to help the team.
The good is pretty obvious. Lowe hits around .260+ walks about 75 times and hits about 17 homers. That's good enough for a 110+ OPS+ which is good enough for Top 10-15 offense in the MLB (1st base has taken quite a dip). Pair this with a Top 5ish defense at the position and you have one of the better first baseman in the league. In a sense in production he replaces what Jesse Winker would have done for the team if he stayed for the full season, though in a wildly different way, maybe even a little better.
What's the downside? On the Lowe side not much. You could definitely argue that what the Nats were really lacking was power and that's the one thing Lowe doesn't bring. This is something that Carlos Santana or Paul Goldschmidt, both signed for about the cost of Lowe, have. He also had his worst power year of his career last year. Is he on the downslide? It's one thing to hit 17 homers. It's another to hit 12.
You can also look at last year and see it's not just luck, pretty much ALL his fancy stats like hard-hit%, barrels, even things related to his patience like chase % went down. If this is the start of a decline he doesn't have too far to fall before he's below average at the plate. And if it was an aberration. one could say the ceiling on Lowe is about as "low" as it could be. He's just good. That's it.
But back to good, Lowe will turn 30 next year so while he could crash next year, you'd be better betting on that from Santana or Goldschmidt. And while Walker isn't OLD (sorry Anonymous commenter) he is old and a better bet to crash thought not to the level of the guys nearing 40.
What about Robert Garcia? I think people are underrating the impact of this move. It's not that Robert Garcia was great. He was a the kind of pitcher that could be special. A lot of Ks, very few homers, and solid against all sides of the plate. But he walked just a few too many and gave up just a couple too many hits and had a bit too much bad luck to be more than good. Can he get to special? Probably! but at 29 next year you generally don't feel bad betting on things just continuing on as is.
No the problem isn't Garcia, the problem is the Nats. Robert Garcia was one of only TWO pitchers that the Nats have in the pen that seemed likely to be good. (Derek Law being the other) Right now the Nats pen is a huge gaping hole and when they are currently relying on a lot of young inexperienced arms and only brought in oft-injured arm to help this spells trouble.
But lucky they have a bunch of money left to help solve this problem!
Soroka was a good move IF they did other things to the rotation. Lowe is just a good move. It's not game changing but it's the type of move that makes sense no matter what the Nats do the rest of the off-season. Hopefully this isn't all they do of course.