<p>Melt-pool solidification predominantly results in misoriented columnar dendrites, occasionally accompanied by seaweed-like structures with no apparent growth direction. The selection mechanisms of these morphologies in the frame of additive manufacturing (AM) remain poorly understood. Here, after performing experimental measurements, we conduct two-dimensional phase-field simulations to understand the coexistence and orientation selection of these morphologies. In particular, we find that the anisotropy function of the solid–liquid interfacial energy plays a critical role in orientation development. We systematically examine these effects in single grain, bicrystals, and polycrystals as a function of the misorientation angle. We explore growth competition between converging and diverging grains composed of dendrite-dendrite and dendrite-seaweed morphologies at both high- and low-velocity regimes, revealing characteristic orientation and concentration patterns. We quantify these effects by estimating dendrite tilt, orientation variation, primary spacing, tip undercooling, microsegregation ratio, interdendritic enrichment, lateral solute gradients, and curvature-based roughness measures. We further employ a regression-based sensitivity analysis to determine the relative sensitivity of these features to misorientation across velocities, anisotropies, and grain geometries. Finally, we develop analytical relationships with new correction terms to represent key solidification features using the data consolidated from all simulations. Our findings suggest that controlling interfacial anisotropy and interface velocity can effectively reduce columnar texture by promoting the formation of seaweed-like structures, providing a viable route for texture randomization and mitigation of anisotropic mechanical property variations in commercial dendritic alloys relevant to AM.</p>