The evaluations on defense for both of these guys are all over the place. Just in what I could see on MiLB.tv (not a great way to evaluate someone but the best I can do) I didn't come away super impressed with Palacios' athleticism in the field. But I've read some very positive reviews from others about his defense. BP said he was a plus-defender and a solid runner. If I was more convinced that was the case, I'd probably have had him inside my top 15 as opposed to 21st.
Well BA has him as the Twins 31st prospect and hadthis to say about Jermaine's defense:
He has above average arm strength and moves better to his right, which should allow him to stay at SS as he climbs the ladder.
From what I saw in the FSL, I'd agree, but he better hit well from the beginning as he is likely starting in the FSL again and has Royce and Wander nipping at his heels.