The blood loss script works good ... doesn't add too many complications, and is really no more "hard core" than RCM already. It actually helps a little with balance when attacking really heavy armor, since wounding a person in extreme armor and then waiting for them to collapse is actually a good tactic (and one that was used). Just be sure to set blood_per_HP to 300 (not 100, as in the listed code), because the first draft had bleeding about 3 times too fast.
I plan to adopt it as an integral part of all future RCM mods.
However, I will confirm that the various formation and morale scripts going around are all known to create some drag on the system. Worse if you plan to use large battles. Not sure how much system drag you are looking at already, but I will confirm the warning.