We examined the structural reconfiguration after intercalating foreign additives, that is, tetramethoxysilane (TMOS), within already formed supramolecular nanolayers of hexadecyltrimethoxysilane (HDTMS). Our experiments indicated that the newly formed interdigitated structure is a thermodynamically more stable configuration. Even after the HDTMS formed initial bilayer-by-bilayer structures, mixing of these aggregates with foreign additives at room temperature can change the original structure to a more compact configuration (i.e., interdigitated). Our MD simulations further revealed that the most favorable organization for this interdigitated stacking appears to be a formation of relatively small domains of HDTMS and TMOS molecules, supporting our proposal of a heterogeneous mixing before reorganization. Although the coassembly of binary or multiple building blocks has previously been used to modify a supramolecule or to produce a supramolecular composite, the modification of already formed supramolecules via molecular intercalation, examined here, provides a flexible path for decorating more advanced supramolecules without disturbing their complex assembly conditions.