We here present a series of classical molecular dynamics simulations (MD) on aqueous solutions of the salts Li5AlW12O40 and Li9AlW11O39, providing us with valuable insight on their aggregative behaviour. Analysis of relative dipole moment orientation in pairs of aggregated [AlW11O39]9- excludes that their large dipole moment is behind their greater propensity to aggregate. On the other hand, MD simulations of the aqueous Li+ salt of the fictitious [AlW12O40]9-—as high in charge as [AlW11O39]