yes but vet horseman have retreat chance of 55% and they win against spearman 50% and lose 50% and those who lost retreat 55% time so 10 of horses will kill 5 spears and you will lose 2 horses
and 10 swordman will kill 7 spearman and 3 will die
on one spear you lose 0.4 horseman and 0.42 swordman
they are the same in killing the units but i like to use horses because they are faster and you can upgrade them to knights and then to cavalary (2 most used units in the game for warmongers)