Geometry limits
If my memory serves me correctly the 345 is geometry limited - usually this means that if rotated too early the tail prevents the AOA increasing to a level that makes acceleration and liftoff impossible ( unlike say, an A4 or something like that) , however , that assumes things like the thrust being at the correct value etc.
If not enough thrust then anything is possible, but that is why the pilot has his hands on the go faster levers.
I could be wrong but even if really badly loaded the elevator and stab power
should be enough to get the thing airborne.
Of course the 345 autotrims the stab when a couple of the engines are started but it is based on the input data to the FM if I remember correctly.
so s%^t in =s$%t out = possible mis-trimmed stab- and that could certainly mess the rotate up and reduce elevator control.
just speculation of course which I agree is not always helpful - just my 2 cents. w