The growing demand for lightweight yet robust materials across various fields has driven the development of ultralight architected materials with engineered microstructures and tailored properties. Among these, truss metamaterials – composed of beam networks arranged in a repeating periodic lattice at the micro and nano scales – have attracted significant interest. While the mechanical behavior of these materials has been explored through numerous modeling studies, the selection of modeling assumptions often lacks consistency and clear rationale, particularly in relation to specific mechanical regimes of interest. For instance, traditional beam theories – such as Euler-Bernoulli, Timoshenko and Kirchhoff-Love – have been extensively studied and compared at the single-beam level, but similar systematic evaluations of their range of applicability to truss metamaterials remain limited. Addressing this gap is critical, as the characteristic dimensions and microstructural effects of such metamaterials are known to challenge conventional assumptions applicable for bulk homogeneous materials. As a first step toward defining suitable modeling approaches for different material properties, geometric configurations, and loading conditions, we systematically assess the importance of including shear deformation in high–strain-rate analyses of truss metamaterials and examine the role of beam joint modeling assumptions (e.g., rigid versus pin joints). In addition, we analyze the impact of different plasticity modeling strategies, including different yield surface definitions. Specifically, the effects of these assumptions are evaluated for several representative scenarios in terms of the resulting wave propagation, energy distribution and deformation modes within the lattice. These analyses provide valuable insights into how modeling choices influence simulated responses. Based on these insights, practical guidelines can be established for accurate and efficient computational modeling, enabling a streamlined design process for lightweight and impact-resistant truss metamaterials.