NB This is not an A340 answer, just a more general thought.
Since TO thrust applies to the TO configs and GA thrust to the Landing and GA configs, you might (however unlikely) be in a situation where a high TO thrust can be tolerated from VMCA considerations (without excessive perf penalties) but be unable or unwilling to use a high VMCL associated with using that thrust as GA thrust. So maybe you would tailor each thrust to be the best balance between high thrust giving intrinsically better performance, and high thrust causing high VMC which then causes poorer performance.
I doubt anyone goes into that level of thought over it, though.