Retarding throttles on a 744/748 at 10-5" is too late.
I'm not sure I agree, depends on many factors including engine type. I usually look at my speed one last time before commencing the flare and then reduce thrust accordingly, it might all come off by shortly after 30' (if, say, light weight, at or above Ref+5 and flying an engine with lots of residual thrust like the PW4062) or at the other extreme I may keep some of the thrust in until touchdown (heavy, gusty conditions and energy level low, especially on a Rolls Royce RB211 engine with its alarming lack of residual thrust).
Straight from our Boeing B744/748 Flight Crew Training Manual:
After the flare is initiated, smoothly retard the thrust levers to idle, and make small pitch attitude adjustments to maintain the desired descent rate to the runway. Ideally, main gear touchdown should occur simultaneously with thrust levers reaching idle.