Particle rearrangement is simulated by randomly rolling each particle across its neighbor's surface. The degree of particle rearrangement per particle condensation controls cluster compactness. Two types of rearrangement are studied: rearrangement during condensation and rearrangement after condensation. We find that rearrangement during condensation achieves higher packing density (e.g. high average coordination number (CN)) than rearrangement after condensation at the expense of coordination number uniformity. We find a region of instability in a binary packing system when large particles are added to small particles. This instability zone has variable, lower packing density regions which disappear with rearrangement.