...let's also assume that since you only have spears, the technology of the age implies that cavalry is in fact armoured...
How about we don't? Since you chose to quote my post, it's pretty unfair of you to disregard the conditions I stated, and then proceed to tear the now-unsupportable scenario to shreds. I specifically stated that when massed musket/bayonets were used as spears, cavalry were not armored.
