I also wonder about Keith at 3B as well.
I thought I’ve heard Jung is better at 2B. I don’t know if that’s true, I don’t know if the theory of swapping them has legitimacy to it.
I think if Jung is promoted and they’re on the IF at the same time, just keep going with status quo to finish this season. Just let them get this bit of MLB under their belts, continue this season with their respective defensive responsibilities, let their bats be the focus of their development this season. If altering them is in the cards, let them integrate some of that individual off-season prep into their upcoming winters, and start that teamwork in spring training. And maybe it’s not that big of a deal for either anyway as they do have experience around the diamond.