As long a defense is factored in there is a lot of measurement error and of course the internal bias of the system that values positions at different weights. It may seem simplistic, but at some point, you have to value run production and run scoring pretty highly. A guy like Schwarber is pretty valuable. He'd be much more valuable on a team like the Cubs who needs run production. I don't know how to factor that in to WAR. Like, if you Put Schwarber on a team with a lot of power, his skill set is not as valuable, but if you put him on a team that needs that type of player, he's obviously much more valuable. I think, like in most instances context matters most.