That was not uncommon at all, and the main reason it wasn’t done all the time was because horses were incredibly valuable so if you kept them alive you could sell them for money or use them yourself.
But there are a large number of weapons that were designed primarily to deal with the horses themselves, including the pike being among the most famous. There are even some examples of gigantic swords intended to be used against horses. And giant versions of caltops designed to cripple horses.
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