Any change that obviously improves the leaving group is acceptable. It would be difficult to improve on the excellent resonance stability enjoyed by this ion, however some creative aproaches might be reasonable. This is why neutral molecule such as water are excellent leaving groups. We consider the factors discussed in lecture with this in mind. Resonance does not alter the electron density of sulfur in this molecule, so it does not influence the nucleophilicity.
Sulfur is a soft atom.
This contributes to good nucleophilicity. Sulfur is not a highly electronegative atom. This contributes to good nucleophilicity. This contributes to good nucleophilicity. We predict methyl sulfide to be a good nucleophile.