I don't agree. The AI needs to make calvalry units.
Players shouldn't have to micro manage their units in tactical battle (AI or human) to be effective. That's why so many of these games are painful -- they are designed such that the "skill" is in monkeying around with individual units in tactical battles. I hate that kind of stuff.
Having skill in tactical battles should matter of course. But it shouldn't come down to dancing around with units, a good battle should be practically over before it starts.
If the AI gets attacked or attacks you with Melee units and you have lots of archers then it deserves to get creamed and you should flame me as an incompetent AI developer.