Large-scale optical packet switching is in a very immature research state. Specially, the effect of the application of the scattered wavelength path operational mode to large scale architectures has not been well explored yet. In this paper, two variants of a knock-out large scale OPS architecture are presented: an output fiber distributed version, and an output wavelength distributed version. Evaluation of these architectures is conducted assuming a previously proposed output wavelength assignment algorithm. It is shown that the traffic spreading features of this algorithm, which provides an optimum behavior in terms of buffer overflow packet losses, also provide a performance improvement in terms of knock-out losses in the wavelength-distributed knock-out architecture. The hardware cost simplifications associated are illustrated by means of an example considering KEOPS switch fabric as the buffered output module of the knock-out architecture.