The cars are close to the same age, and not too far off on miles. I’ve not been impressed with Jeep Liberty as they age. The can be trouble prone, and electrical gremlins are particular problem area that are difficult to fix in this car.
I’m not a big Subaru fan either, but in this I think you know more about the Subaru due to past service records. I’d really look over the documentation and look for any head gasket issues, perhaps they have been dealt with previously.
Between these 2, in this case I’d opt for the older Subaru.