the pro way to do it is alt+left click a tile and it will show everything on that tile in the top right window. You can then just click the person in that window and slash them/drag them/whatever. Also works with stacks of items. Instead of right clicking and lagging for 50 minutes just alt+left click.
That only works if you are next to the tile you want to check in. Directional slash is faster.
What is this directional assist it says i have it on but i see no difference i just click on spessmen and they get slashed or disarmed depending on intent i see nothing just kill