You are not alone in wanting to avoid trading any of our better prospects for rentals. I am with you on this.
With Bregman out and Meidroth traded away and Devers, too, we had to play players where they are not a good fit. (Toro has played 3B in his career, I might add.)
IMO, the Romy-Toro platoon at 1B and the Abreu-Refsnyder platoon in RF are two big reasons we are still in the WC race. I'd like to see Mayer play FT 3B, until Bregman returns, but that does not fix your "out of position" issue. Who would you play at 3B?
I was fine giving KC a very long look at 2B, but he was doing very badly on defense, and then he seemed to totally lose his batting skills. That went on for a very long time, too. DHam has a very nice 2024, so I can at least understand why they gave him a lot of reps vs RHPs. I'm not sure what other options we had, other than Mayer at 2B (out of position) and then Toro at 3B (not 1B, where he has played good D.)
Some players have not worked out, and Cora made changes- kinda like taking Weissert out when he was sucking.