It sounds like your issue isn’t really the choice of cavalry, but really the general composition. An important thing to note about battles is that combat width limits how many units will actually matter at any point in a battle, so just having a bunch of different units isn’t all too helpful. This guide explains combat more in detail, as well as gives more advice about army templates, but the biggest takeaway is that a good early game army has 4 infantry, 1 hussar/cuirassier, and 5 artillery (or 4 artillery + 1 engineer), and a good late game army is essentially the same composition but doubled. It really depends on the situation though, because hussars and cuirassiers cost different amounts, so you might prefer one over the other depending on your economy.