Any landing gear designer would tell you that they "have to put the trucks in some sort of orientation" hence the truck tilt actuator & usually in a toesup position. Airbus & Boeing do use the actuator to position the trucks to fit in the wheel well - as well. THe 777-300 with the semi-levered gear positioner - acts as a landing gear snubber on landing to1) reduce body stress on landing for longer structures life & landing comfort, 2) raise the airplane up prior to takeoff to increase aft body clearance margins to maximize takeoff alpha and hence performance & 3) position truck for stowage. I was addressing why the landing gear on the A340-500/600 was a mixture of toesup & toesdown configurations - again because the body & wing gear are not on the same centerline & exploiting truck beam length to put the wheel where they need to be. Landing gear designers prefer the toeups configuration because of the springback loads generated - again - draw a freebody diagram for yourself & check it out ! I dont think the 767 is a toes down configuration - I dont think they would do a config like that unless they had to because of landing gear stress ..
Tallbloke - if you place the landing gear before or aft of the centroid - the airplane will experiance a pitching moment or heaving fore or aft depending on where the moment of inertia is in relation to the touch down gear ( IE the fulcrum). Not a good thing - some modern fly-by-wire systems use the INS inputs to the PFC to wash in elevator to cancel this phenomenon as a function of pitch rate on landing .. but - better not to have the gear placement problem in the first place ..