I have been struggling with making a diverse cast of units based on various classes I’m using for a potential rom hack. But this thought process turned into a question that could help me learn more in the future.
How do you handle unit classes when designing your rom hack?
A lack of class diversity doesn’t mean a lack of diversity in terms of gameplay.
On the contrary too much class diversity from the get go can be overwhelming for the player or make them loose interest in the futures units. (Or not, kinda hard to tell)
Linking this topic because it might be relevant to this.
As for promotions,
Getting rid of split promotion can be a good thing if you plan on adding new classes for your units, because it would otherwise be a headache to make the new class fit in.
Screw class diversity, everyone’s a Swordmaster or Swordmaster adjace-- …I may have the same issue.
*monster
I have these thoughts whenever I design a unit,
I believe that there is little reason to hyper care about class diversity in design, obviously you don’t want a third of your cast to be armour knights but all FE games have an imbalance fe7 has one shaman but 3 mages, it has 1 nomad but 3 archers.
to go over why I have these thoughts when I design units
Pretty simple really would this unit be this class, would they use these weapons, would they wear these clothes/armour, would they fight like this. Obviously a noble won’t typically be a brigand, often poorly dressed, unrefined fighters that use the axe.
Also pretty simple would a unit in this class be in this circumstance, horses are more likely to be used on fields, holy mages are more likely to be with the church, or some other religious/religious adjacent organization, if they are from a country that is knowen for heavy armoured troops like ostia, armour knights are fitting but a character from Bern while being an armour is still sensical a wyvern is more fitting, if all the troops recruited from Bern where armours it would still feel weird because their use of wyverns is emphasized.
This is more a case by case basis, with a larger cast [approx 40-50] I feel 5 is a good maximum number of one class type, as more than 5 becomes harder to differentiate units, and the class becomes a noticeable part of the cast, for smaller cast sizes you will have to adjust I think 3, for smaller cast [30 and below], would work out well depending on the classes, you could probably get away with 4 cavs but probably only 2 thieves.
You could still go beyond these limits have 7 cavs if it fits your vision, it will probably be better if you do so over fixating on having even mix of all classes, none of these are hard rules, you can ignore every one of them, I just use these guidelines as it works for me.
Even though I technically don’t have a proper hack out yet, the thing I look for is:
A.) What does this unit bring to the table that the others don’t already when this one joins?
B.) When should I put a replacement that both makes them useful at that time and is optimal if ever you lose the previous unit?
Of course, these two points come with every grain of sand imaginable since I love having as many unique classes as possible cause I like having as many cool-ass animations as I can reasonably fit, so they might be obsolete for you, but I feel like they still apply regardless of that, so yeah 
Starting with point A, it’s important to take into account what this unit has access to that the others don’t and, if they have skills, how they interact with either their combat/utility or others’. For example, say you have two lords (wacky, I know :333); then say one’s got Charm and the other Voice of Peace. Then you can battle with two forces on certain maps and have an equal balance between them, and it’s a win-win 
Then with point B, I like trying to have a mix between FE1’s and FE7’s unit philosophies; each unit you start with is unique, yet if you lose one, then another round the corner that’ll both fill in the niche that was there before and be able to at the very least contribute out the gate (perhaps needing a sprinkling of investment here and there). While yes, it may seem random and kind of silly, it ends up feeling smooth and cohesive. I’d say an optimal time between the original and a replacement is around 5 chapters or so; you get time with that OG character, but if they somehow die along the way, then it’s not too far off for their niche to be filled 
I’m probably just spitting the same opinions everyone else has already, but I’d like to think that these points can help fill out the cast in terms of the available roster and what they bring to the campaign, at least on the gameplay side (or make it worse, I mean again this is from someone without a single hack to her name ). I hope this helps 
Spawns halberiders, lance paladins, generals, and wyvern lords reforcements
lance reaver yo ass
Class diversity is an illusion. Units are their capacity to fulfill objectives. Kill enemies, warp/buff your guys, debuff enemy guys, that sort of thing. A lot of romhacks overcomplicate things with skills and prf weapons that are only useful in extremely niche cases.
One shot with low def and hp
dodge tanks and crits back
Wyvern lord pulls out an axe
switch to killing edge and hides in bush
Halberider pulls out a killer lance
my sword peg comes in and rescue canto to safety
Oops greatbow sniper with 3-10 range shows up
Sleeps by my sword sage
Max res sniper with staff guard
lmao me and storm blight be playing chess, let’s uh take it to dms bro
Nah I’m good was just messing around