In the current alpha spear cavalry isn't very effective in battlefields but in women raids. Since Sword cavalry were used in battle for out flanking enemies and deal a critical strike to the backward lines, I thought that increasing their movement speed would help them in that task and in escaping from Spear Cavalry which is more effective vs other melee cavalry because of their higher range and impact on the rider. I thought that providing them a 1,25x would give them a more deterministic role letting unvaried the performance vs most of the units f.e. skirmish cavalry is still able to defeat spear cavalry.
elexix, for the Cavalry speed buff ticket you posted, I think that corral tech should have a conseguence like granting to cavalry a higher movement speed at disadvantage of their capture points