Interesting note about Kirk, he's actually not having all the bad of a hitting season if you look under the hood. His BABIP on the season sits at a lowly .257, which even with his poor foot speed is uncharacteristically low for a hitter with his all-fields, line drive approach. He has a .339 xwOBA, which is a 53 point underperformance from his actual wOBA. Sure, you can claim that Kirk will always lose a bit of expected output due to his pathetic baserunning ability costing him numerous infield singles and doubles, but never to this extent. His avg. exit velo and xwOBA sit comfortably in the 70th percentile, he doesn't swing and miss, draws a decent number of walks, and he's never been a barrel chaser but does connect hard.
If his underperformance was more in the ballpark of 10-15 wOBA points lost due to his legs, we'd be probably be looking at him with a ~110 wRC+ and comfortably providing 3-4 WAR of value.