This paper demonstrates that the scattering cross section per unit length of randomly oriented linear chains of optically soft spheres asymptotically converges toward those of randomly oriented and infinitely long cylinders with volume-equivalent diameter as the number of spheres increases. The critical number of spheres necessary to approximate the linear chains of spheres as infinitely long cylinders decreased rapidly as the size parameter of an individual sphere increased from 0.01 to 10. On the other hand, their absorption cross section per unit length was identical to that of an infinitely long volume-equivalent cylinder for any number of spheres. However, this approximation does not apply to the angle-dependent normalized Stokes scattering matrix element ratios.