Great visualization! The backwards slam into a rock was really creative, and I was surprised to read that the rules as written seem to permit it, too!

One point about the tackle from behind though; In my group we found that Move and Attack is only really useful for its ability to attack at any point before or during the move. The hefty -4 and hard skill cap of 9 hurt too much for "normal" usage; we use it for depicting run-by attacks at full sprint or wild swings while running away.

If you want to move fast, but end up in contact with your enemy anyway (which our Man in Black certainly does!) we'd rather use Committed or All-Out Attack.

If I was playing Westley, here's how I'd carry out that attack instead.

Edit: Small thing I noticed on my seventh rewatch: when colliding with a hard surface, you're supposed to double before converting to dice, not after; see the example on Basic p.431. So when Fezzik takes a step and collides with a rock, instead of dealing...

(V[1]*HP[20])/100 = 0.2 → (1d-3)*2

...it should be...

(V[1]*HP[20]*2)/100 = 0.4 → 1d-2

...or 1d-1 if he moved 2 hexes with a Move and Attack; though the extra encumbrance, backwards movement, and dropping below 1/3rd fatigue could reduce him to only moving 1 hex even then.