Reference please
Well for starters, there is nothing in the game rules at this time except for a Quirk, which is by definition optional.
When the
Behemoth was introduced to the BattleTech universe in 1988 with
DropShips and JumpShips, the construction/space travel rules at the time postulated that a DropShip required two docking hardpoints for every 60,000 tons (or fraction thereof) of mass to dock with a JumpShip. There was no explanation given, and the only statted vessel of over 60,000 tons was the
Behemoth.
The rule has since been dropped and doesn't exist anymore, and Quirk rules didn't exist back then.
The "Large DropShip" Quirk post-dates the introduction of the
Behemoth DropShip by some twenty years. The
Behemoth is explicitly listed as the poster child example for this Quirk though so the impression given is that the Large DropShip Quirk was actually tailored for and by the
Behemoth.
The only explanation ever given is the wording in
DropShips and JumpShips: "The hull is so enormous that it takes up the space for two vessels when docked with a JumpShip."
To wit, that means they still require only one collar for jumping, and can still be carried on a
Scout class JumpShip with its single collar. Conversely, it wasn't ever said anywhere that they required two collars for jumping. Personally as a GM, I probably would still allow very small DropShip (such as a
Fury,
Buccaneer or
Leopard) to dock next to a
Behemoth.