We present a simple model for the discrepancy in the coverage of a gold (111) surface by two silicon phthalocyanines. The model involves random sequential adsorption (RSA) simulations with two different landing molecules, one of which is tilted relative to the substrate surface and can (under certain conditions) allow neighboring molecules to overlap. This results in a jamming limit that is near full coverage of the surface. The nonoverlapping molecules reproduce the half-monolayer jamming limit that is common in continuum RSA models with ellipsoidal landers. Additionally, the overlapping molecules exhibit orientational correlation and orientational domain formation evolving out of a purely random adsorption process.