Scene Context: John does not attempt to "pull" two surviving BSC reactors using just the lifeboat's thrust; instead, he uses other reactors as "cue sticks" to impart the necessary vector and assemble an improvised convoy before entering the scar.
Essence of the Phenomenon: This relies on rigid adherence to classical physics. A small spacecraft with a limited momentum budget cannot freely maneuver multiple multi-ton masses unless it utilizes their own thrust, mutual momentum, and approach geometry. Therefore, the scene operates like a game of billiards: it relies not on direct towing, but on momentum transfer between large bodies via precisely calculated impacts and magnetic-plasma shunts.