The original Taylor principles offer identical intergranular strain equilibrium without stress equilibrium in metals during deformation. In reality, however, the stress and strain equilibria are maintained individually for different grains. As key points, the principles have become a prerequisite predominantly in the current theories, which unreasonably indicate that strains instead of stresses induce grain deformation despite reaching the stress equilibrium by complicated combinations of the activation of slip systems or other crystallographic mechanism via different approaches. Real intergranular equilibria can be traced if mechanical interactions together with the external loading are considered step by step. In this work, several penetrating and non-penetrating slips were used to obtain the necessary elastic and plastic strain tensors of different grains in a natural manner. Without the Taylor principles, the stress and strain equilibria can be reached naturally, simply, easily, reasonably, and individually without complicated calculations. Results of the experimental observation conformed with the predicted deformation texture when certain important engineering stress conditions are included in the simulation. Therefore, the Taylor principles for plastic deformation of polycrystalline metals should now be disregarded.