Welcome to the forum, you deserve a break from that ape. Goodspeed.
Much worse than you assume, even. I.e. using wet numbers on a dry runway is an AFM breach (screen height and TOD calculation).
For your landings, use the FCOM/FCTM diagram. Your visual aiming point is always 297/300 m from the threshold. Runway markers and PAPI could be all over the place, namely the easterly RWY in Ho Chi Minh is 450 mtrs. Learn to use PAPI and the makers as guidance until a wise moment but no longer, then identify the true aiming point, eyeball it and fly the plane there.