What would I do with them with my limited warfare understanding?
Here is why they are the prefect skirmishers. First they are taller which means they can stand behind your infantry and shoot at the enemy.
They are stronger which means they can maintain a higher rate of fire with better damage, more on that later, and lastly as they are bigger they are even faster than normal humans.
- Their larger size will allow them to draw the same bows humans use to kill one another, think English longbows, at a higher rate of fire. Please do not make the mistake of giving them larger bows to have maximum total overkill. An English longbow is plenty enough to murder most people. However the increased rate of fire, because they are stronger means you can keep shooting arrows and throwing stuff longer. That is perhaps a better killer than anything else.
- Slinging bullets, small rocks that has a particular shape, is a very viable usage for them. Here, as always, Newton proves to be the most dangerous man in the world. As they are stronger which means you can scale up the projectiles a bit, context of course, and still maintain a decent rate of fire. Normal human slingers existed and so giant slinger would be better.
- Throwing spears, darts, axes, or javelins...etc is a again perfect. Here you traded the range of arrows, yes medieval arrows were not guns but that's a whole other thing, and went for raw power. Again not giant stuff but say 25% bigger weapons. And you can imagine what a 25% bigger pilum would do to people.
- Their larger size allows them to move much faster than normal people so they can be deployed to harass the enemy and once the enemy tries to pursue or attack them they can just retreat. This is a 100% historical tactic.
- This also allows you to simply armor them with simple and basic stuff, like chainmail, and a shield. A shield seems a must especially because they are a bigger target. Shields are a lot cheaper and plentiful than plate armor.
- Armoring them in actual armor is very expensive but also problematic. Especially as they have larger joints which automatically mean larger gaps and a weaker armor. We all know the knees or armpits...etc where week points and with a bigger target
you will be be forced to provide more materials, more money, and then raw strength is not the biggest issue.
- The enemy can simply counter you with a shield wall or phalanx or whatever else they can do. They don't have magic abilities and will still be killed if they charge a phalanx.
- Of course they are still not a super force. Arrows can be blocked with shields but because you can produce a much higher rate of fire with them then I think they can do more damage in an ancient battlefield than if they were infantry.
- Anti giant cavalry will be a thing. Whither pure mobility or pure armor I'm sure they will be armed with super long lances to counter giants. Then you deploy your own giant protection units and it is business as usual.
- This also applies to skirmishers. The enemy would use their own giant skirmishers but that is just the nature of war.
If you really need to use them for melee units then I think they can be the best at the flanks. Why?
Think about it. They are stronger and fast so they can execute a better flanking maneuver than anyone else. They can also turn much faster to face an enemy.
Just make sure to give them decent shields.
A no brainer really. Not because they are stronger but because they are taller which means they can see further, again context, and shout louder and carry a banner or walk faster. They can be a figure of rallying the troops around and it would mean that your own officers are courageous and strong.
However Sun Zu clearly warns of the disparity between officer and soldier. Never have a gap between both. He says :" When the officers are too strong and the common soldiers too weak, the result is COLLAPSE. When the common soldiers are too strong and their officers too weak, the result is INSUBORDINATION."
So bear that in mind.
Overall I think they would make excellent skirmishers and overall excellent support units. I mean I would suggest runners or watchers or just keep them as officer but honestly I think you want to include them in more fighting rules.