ya,i too think so.
but,another factor dat the relative solubility of Ag and Au is too high than solubility of other 2 metals , as Ag and Au are soluble forming soluble complexes wid aqua regia.
Atomic chlorine forms metallic chloride with gold.
Au + 3[Cl]- → AuCl3
Metallic chloride then reacts with HCl to produce hydrometallic chloride.
AuCl3 + HCl → H+[AuCl4]-
Hydrometallic chloride is soluble in aqua regia.