It really does depend so much on the era and culture.
and they have one on oriental warfare and ancient and naval.
here's a good place to start digging. As far as I know there werent all that many manuals on warfare. Some of the more advanced societies sure...the Byzantines wrote one. But as far as how much they adhered to it....I would think more of a training manual. because when it came down to it a good commander had to adapt to the situation both strategic and tactical.
Do a search on Youtube for medieval warfare
esp shadiversity channel
and Kings and Generals
also History Marche
Understand that much is the product of the society and environment. If its mostly forest you wont see alot of pikes, but will see bows. If the society doesnt have ready access or cant afford metal to make metal armor they would need to make lighter armor from other materials.
Some, like in britain at the time of the Norse wars would fight in formation, a shield wall. Often this became a shoving match and whoever broke first would be at a disadvantage.
Some, like the older german tribes fought in a looser formation and rushed the enemy hoping to overwhelm and break them. I would venture that most didnt have manuals but had traditions. You should be able to discern these by google or just by reading battle accounts.
There were many differences. For example the impetuosness of Chivalric Knight cavalry. And this could be exploited...as the mongols did. I've never read of the Mongols having written manuals but they had traditional ways to fight.
Pre-mech? That covers so much ground. Once you do get to firearms and cannon it starts turning into a whole other world. You can also google warfare in a particular book series...like malazan.
Just a quick couple ideas, and it depends on many variables. What an army could do depends on the skill of the commander and the training and morale of the troops. The Total War series of games lets you choose different cultures and set up battles and you choose the opponent and their troops or AI does. You can also fight against people online. Its not perfect but would give you a taste. Also remember that a battle doesnt exist in a vacuum. It is part of a campaign and has happened in the setting it has because of strategy. Also, in different periods and areas armies were raised and commanded differently. That had an impact on command and control. If you have a weak king and strong nobles...each noble sends men and they are lesser under control of the commander. Whereas a strong King will actually command those noble's forces...or his general will. And they will obey or else. For much of medieval times a king could call up nobles' forces for a limited period, after which they could go home. Example...someone would have to harvest the crops. When more standing armies came about they formed a core and the levy could be called up to help. Many differences over time and area.
https://www.google.com/search?q=medieval+military+terms&rlz=1C1CHBF_enUS916US916&oq=medieval+military+terms&aqs=chrome..69i57j0i22i30l2j0i390l3.5541j0j7&sourceid=chrome&ie=UTF-8 here's some good stuff for medieval military terms.
have fun