Strategic Operations states of p.191 "Each ’Mech or vehicle can recover one unit (for ’Mechs, see Dragging a ’Mech, p. 99, TO), though the unit must be of equal or lesser tonnage than the dragging unit."
This references p. 99 of Tactical Operations which states "In place of picking up a ’Mech, two friendly ’Mechs may attempt to drag a disabled and/or abandoned ’Mech (friendly or enemy) from the playing area; a friendly immobile ’Mech can be dragged in this fashion, but an enemy immobile ’Mech cannot (it must be disabled and/or abandoned)."
I checked the errata and did not see any clarification. So does it take 1 'Mech to drag a salvageable 'Mech off the field or 2?