  We analyse the contribution of $2n$ scalars to the Operator Product Expansion
series for MHV gluon scattering amplitudes/polygonal Wilson loops in planar
${\cal N}=4$ SYM. Hence, we sum up on $2n$ for large coupling $\lambda$: the
logarithm of the amplitude is proportional to $\sqrt{\lambda}$, thus competing,
unexpectedly, with the famous classical contribution. We give explicit
expressions for the first terms at large $\lambda$ in case of two and four
scalars. For finalising this analysis, we find profitable an explicit
computation of the $2n$-scalar term at any coupling by means of Young tableaux,
paralleling, under certain aspects, the Nekrasov-Okounkov expressions for
$\mathcal N =2$ SYM prepotential.
