Asymptotic Analysis is known as a proper method in treating Electromagnetic problems regarding electrically large structures. However, in this article, this method is employed in order to compute the mono-static Radar Cross Section (RCS) of a relatively small complex structure. In this regard, Asymptotic Analysis is performed on the scaled model of a surface naval ship through the frequency range of 100 MHz to 10 GHz and the results are compared with those obtained by Integral Equation (IE) method which leads to exhaustive and time consuming computations compared to Asymptotic Analysis. In addition mathematical methods named Dynamic Time Warping (DTW), Hausdorff distance, and Average deviation have been incorporated for evaluating the similarity of results obtained by Asymptotic Analysis and IE method. As the structure's D/λ exceeds approximately 5, the convergence of these two methods for RCS computation becomes satisfactory.