Madchop in its current iteration is a standard autohit at its worst, and the greatest autohit in the game at its best. Everywhere you look, people are charging, whacking people for 150-200 damage or more, and knocking them away 15 tiles. People have (half-jokingly) said it's a better version of Ether Invitation, just because of the raw damage it puts out. This change doesn't detract from Mad Chop's identity as the OW autohit, but it gives it a better niche. By making it worse than every other soldier autohit at full health, it prevents people from doing nothing BUT charge madchop.

Execute has the scaling of a normal autohit before the missing health is taken into account. However, the missing health damage is extraordinarily low. One might glance at 25% health and imagine killing someone at 40% hp, but in reality, that bonus damage is just 15% of their max health. Which, on average, is between 45 and 75 damage before resists and defenses are even taken into account. Considering the prerequisite of someone being knocked down, and the fact that Execute CURES the status, it needs to scale more than a touch harder. It's very difficult to use Execute when you fight in one versus one, because knocking someone down and Executing in the same turn is not easy. (The notable ways of doing so being charge+bash with flatfoot, dense thunder, and crane hop axe kick. Only one of these works outside of melee range.) This change makes using the ability worth using at least once in a while, and grants it more weight that you would expect of a move called Execute.