An interesting thread.
There are many symbolic differences. In RWS the Fool is seen from the left, ostensibly the yin or feminine side. In the Marseilles he is seen from the right - the supposed yan or masculine side. Of course this is overlaid symbolism and may have nothing to do with contemporary meanings.
I think the Fool in the Marseilles could just as easily be construed as walking off a cliff as the RWS Fool if you look at the image closely.
There is also a visible Sun in the RWS image and not in the Marseilles. The Fool has an exposed buttock in the Marseilles, not in the RWS. Both characters are in different costumes of course. The RWS Fool carries a flower, whereas Le Mat has a staff in the hand that is not carrying the bag. Have you noticed how Le Mat’s left hand is oddly turned over his right shoulder? That is quite a strange position, and what does that mean, if anything? Le Mat has a beard where as the RWS Fool does not. The Fool looks younger, more innocent than Le Mat
I have always seen the RWS Fool as not being at the beginning or the end. Different decks have their own approach. Different authors also put Le Mat at the beginning of the journey, some at the end. Just a cursory look through the Encyclopedia of Tarot shows many different interpretations of both Le Mat and the RWS Fool.
It all seems to depend on history and which school you decide to follow, I guess. I see the fool as being the spirit of freedom that comes from being in a state of grace. Amadeus . Quite blessed, with the peace and joy which comes from that. In this life it is always transitory.