You are all right about fs_slow and the rest. In some speed tests some time ago I notice that the walk animation was the same for all the skeletons, whereas the only difference was in the run animation (I did not try the attack animations). Something similar happens with horse animations. Rapid and slow horses are only different in the galloping animation.

@xeres

I don't know what version (vanilla or moded) are you using for the tests. There is an additional "point of confusion" regarding the tests: the lethality.

The last value in stat_pri is the lethality of the weapon, and they are always 1 in vanilla with only two exceptions: 2 handed weapons (0.87) and spears of non-phalanx units (0.73). If your tests are on vanilla version, the victory of spears with 0 delay is even more surprising taking into account these values.

In ITW the lethality has been balanced (reduced greatly) to produce longer battles, with lower casualties (in an attempt to improve the realism) and depending on the type of weapon.