To my knowledge, Fallout 4 doesn't give you the option to set your companions following distance or aggression level like previous games, but it looks like they still scripted some dialogue for it...
Here are some responses I pulled from Deacon's script for when you ask him to close his following distance:
"How close we talking about? Do you just want a hug?"
"Being so close, well, let's just say I work better from the shadows."
"If you wanted me any closer that'd make me nervous."
+ bonus, when you ask him to be aggressive:
"Right. Time for me to get aggressive. Rawr. That sounded threatening, right?"
[source] [video] <- credit to @amazinglyegg for finding the audio recordings for these lines









