Huddle with coach during free throw?

[cozzmokramer]

Just wanting opinions on this tactic.

On every two shot foul a coach always brings his four players over to his sideline while his player shoots the first free throw. The four players huddle around him with his whiteboard, then after his player shoots the free throw those four players take their spots in the FT lane.

Just curious if these de facto timeouts are legal? I'm not saying this isn't good coaching, but just seems like it's an unfair advantage because the other coach can't bring all of his players over during this time even if he wants to because, I believe, the bottom spots have to be filled even on a 2 shot foul, correct?

Just wondering, what, if anything should be done with this tactic?