Depending on whether you had engine hydraulics or not, the commit point for landing was flap extension or gear extension
If you are manually extending the gear, it is likely because you lost A hydraulics which control gear and normal operation of flaps both on the leading and trailing edges. If A system has been lost(due to #1 and #2 engines out) do you not commit to land not at gear extension but earlier, at initial flap extension due to the inability to now retract the LED's?
As the TriStar has four independant hydraulic systems, redundancy is enhanced considerably over other three engine designs.
Does this three engine design have manual reversion in case all hydraulics are lost?