If the result was equal to greater than the runway available a static takeoff was required
A matter for corporate risk assessment.
However, I consider that
(a) a reasonable view, provided the concern is restricted to ASD considerations, when considering standing start on the brakes compared to progressive thrust application. Otherwise it is an excessive conservatism for the majority of situations.
(b) but not for a rolling on start where the aircraft is moving along at a clip and the thrust setting is prompt. Typically, this is the case for a 90 degree roll on where the turn is continued into the takeoff without stopping and the spin up occurs in the latter part of the turn .. ie the final thrust increase occurs as the turn is completed and there is no dilly dallying trying to get lined up on the centreline prior to thrust setting
Some engines were first set at a mid-range power setting prior to brake release
For a rolling start this is the aim .. we want the final thrust acceleration to be in the higher acceleration range. Keep in mind a rolling start does not include a progressive thrust setting from a stationary start. Chalk and cheese, although, for near gross weights the difference brakes on/off is pretty trivial.