They both play lazy. It's annoying, but at least Marte has enough raw talent to make up for it most of the time. Polanco just sucks.
They really need to get rid of Sean Rodriguez. He's god awful and Hurdle uses him way, way too much. There's really no need for him when they have some talent in AAA, like Kevin Newman, Adam Frazier, and Jose Osuna. Osuna is crushing the ball down there, hitting nearly .350 on the season.
Another addition in the future could be Jung-ho Kang. He was activated off the restricted list a couple days ago and has been playing in AAA for about a week. He's not hitting well (2 for 17) but he's not striking out either, so hopefully that comes soon. He's been playing both 3B and SS, which could open the door for a Jordy Mercer trade, who will be a FA after this season.