I really don't like that idea. Kiermaier had a 90 wRC+ last year. Gallo's was 85. I expect at least some rebound from Gallo, but some of that would likely be balanced out by a slight drop from Kiermaier. It obviously makes the defense a lot better, but I would argue it actually makes the team quite a bit worse overall.
That's why I think it's worthwhile to pay more for Nimmo: he improves the defense over Teo/Gurriel AND improves the offense. I love the idea of adding Nimmo while also trying to get a guy like Kiermaier as the 4th OF who gives them an "elite defense" lineup with Nimmo/Kiermaier/Springer in the OF now and then.
I'm just more risk averse than anyone. I'm very conservative when it comes to free agents. I even look at our biggest deals and they have all aged pretty poorly so far except for Gausman and Springer;
Morales: paid $33M for 0.8 WAR
Roark: paid $24M for -0.6 WAR
Ryu: paid $80M for 2.1 WAR
Kikuchi: paid $16M so far for -1.1 WAR
Berrios: paid $10M so far for -0.5 WAR
Grichuk: paid $33M for 1.9 WAR
Gausman looks great but its year 1 of 5. Berrios should bounce back but he has 6 more years if he doesnt. Springer has given you 6.4 WAR at $53M but with WAR at $9M per WAR he is giving you $57M - dont anticipate that ages well over the final 4 years.
We have been much better on our 1-2 year deals;
Semien: $18M for 7.3 WAR
Ray: $8M for 6.6 WAR
Oh: $1.25M for 1 WAR
Hudson: $1.5M for 1.3 WAR
Galvis: $4M for 3.0 WAR
Shoemaker: $7.7M for 1.7 WAR
Phelps: League minimum for 1.1 WAR
And then you have some not great to bad 1 year deals; Estrada (2nd time), Granderson, Garcia, Axford, Chatwood, Shaw etc.
But thats the thing, they are 1 year deals, fall off the books and doesnt hurt you. Which is why i like Kiermaier, Brantley and or Gallo. If Nimmo regresses or gets hurt, well you stuck with it for another 4-5 years and it limits your spending.
Now this doesnt bode well for me because i advocated for signing JBJ (-1 WAR) over Springer (6.4 WAR) and Ray (2.1 WAR) over Gausman (3 WAR) and i said i liked the Kikuchi and Berrios deal all things considered. But i tend to stay away from long term deals because you have what is happening now; Ryu and Grichuk took away $30M of spending on the 2023 roster.