  We disentangle the contribution of scalars to the OPE series of null
polygonal Wilson loops/MHV gluon scattering amplitudes in multicolour ${\cal
N}=4$ SYM. In specific, we develop a systematic computation of the $SO(6)$
matrix part of the Wilson loop by means of Young tableaux (with several
examples too). Then, we use a peculiar factorisation property (when a group of
rapidities becomes large) to deduce an explicit polar form. Furthermore, we
emphasise the advantages of expanding the logarithm of the Wilson loop in terms
of 'connected functions' as we apply this procedure to find an explicit strong
coupling expansion (definitively proving that the leading order can prevail on
the classical $AdS_5$ string contribution).
