@SoaringHawk218 , I have a few questions to ask I think Ryza would know, mostly just worldbuilding stuff I want to know because I like the setting you're making.
I'm glad you like it
1. Which classes are most common in each faction's armies? I assume the Fighter/Soldier/Mercenary trio is somewhat omnipresent, but there seems to be an implication that each kingdom has a class or two they have a lot of, like Agrithe and Yeomen.
Of the groups she knows, Agrithe focuses primarily on yeomen, though they also have a contingent of fighters that don't often get to do a lot since the horse archers do most of the work. Parves is mostly cavaliers and armor-knights, Rignali has light foot troops like myrmidons and archers, and Hornglade (who's providing most of the Northern defensive troops at the Starhelm front) has a fair few troubadours to back up their own light cavalry contingent.
As for the Empire, other than their wyverns, they have a strong soldier core, more-so than even the norm, backed up by cavaliers. She's pretty sure she's seen for a decent percentage of the yeomen they even
have already. From what Ryza's heard, they also typically enjoy magical superiority, but mages are thin on the ground right now for them. Legerius has a similar troop spread to the Empire, and the Whitewings are of course nearly 100% pegasus knights.
Ryza hasn't seen much of the Divine Realm's army, but it probably weighs heavily towards White magic casters backed up by durable infantry, probably mostly soldiers and armor-knights.
2. Seals seem to be very rare. How many are there, or does nobody know for sure? How many do the Southern Kingdoms have, and how many are they willing to use?
Yep, they're pretty rare. Ryza hasn't seen any Sealed combatants in this fight, though from what she's heard there are a few Paladins among the Imperials, which probably means there are also a few infantry with Seals as well. You know that Selena, Artemis's first retainer, was a Paladin too, but her Knight Seal was lost when she was killed. Among the Southern Kingdoms, there are probably ten to twenty Seals of various types, but none of them came north with Artemis's force. They're probably being used to punch through the Southlands dutchy's defenses.
Mostly, Sealed combatants aren't risked in low-level raiding and skirmishing, which is what has mostly happened until now. They get brought out for the big battles or when overwhelming force in a small package is needed. Nobody knows exactly how many there are, but they're very hard to make, and as such are a strategic resource.
3. Does Ryza know of any time before her slumber where the manakete had to fight a war?
As far as she's heard, never. There are stories of a few inter-tribal conflicts where blood was shed, but the Arbiter was usually able to jump in before anyone was killed. The worst she'd ever read about was a long-running dispute that ended when a group of young hotheads from both sides got into a big brawl. About five manakete died in total, but they devastated the local area.
Of course, she knows that
something really bad was happening that her parents hadn't been telling her about, and she doubts her parents went down without taking at least one of their attackers with them.
4. Are people in universe aware classes are, well, a thing? Or is it just different combat roles that happen to stumble into them by happy accident?
They wouldn't refer to them as such, but a lot of groups develop similar ideas. For example, the Empire wouldn't call their horse archers yeomen, they'd call them something else, but they recognize that they fulfill a similar role in battle. Agrithe and the other Kingdoms have just doubled down more on that sort of training since they have less heavy armor production than the Empire, so they focus more on mobility.
5. Who was the strongest manakete Ryza ever heard of? Besides her parents, that is.
That's a bit of a tricky question. In general, the older a manakete got, the stronger they were, though at some point they'd get too old to do much of anything. That, however, tended to happen very suddenly, so as a rule of thumb if a manakete was older than you, they were probably stronger as well, if only by a bit.
However, in general the strongest manakete at any time was the Arbiter. Now, the Arbiter wasn't chosen
because they were the strongest, but when they received the True Stone and gained the Mother's blessing, they took on traits of all the tribes, which meant they had functionally no weaknesses. They were almost as physically strong as a Red, almost as fast as a Green, almost as stealthy as a Black, almost as magical as a Yellow, and almost as resilient as a White, all at the same time. Going back to your question about manakete wars, one of the reasons they didn't get worse was because the Arbiter would step in to moderate and defuse the situation, but if anyone tried to use force to overrule their judgements they were perfectly capable of smacking that person down. Everyone else tended to listen after that.
Of the manakete Ryza would have heard of, she'd heard there was an old Red Lord that'd gone hermit east of her home that her mother said was the biggest, strongest old manakete she'd ever met in person, and her father had always spoken highly of the elder that lived at Goromasa-Zez-Akvech, what the humans know as Sundered Peak.
Hope that all makes sense.