Complex sentence: The tac headquarters is a small collection of staff and communicators usually very mobile, they exist to allow the Commander to get forward in an operations and command the key parts of it from a position where they can see the ground and influence their immediate subordinates.
Split into simpler sentences: The tac headquarters is a small collection of staff and communicators. Usually very mobile, they exist to allow the Commander to get forward in an operations and command the key parts of it from a position where they can see the ground and influence their immediate subordinates.