Hi! So, I’ve been working a ton my first official hack, FE Steel Will, and I’ve been tinkering on how enemy’s stats scale across the campaign, and I’ve been wondering if there are any other strategies to make this work without throwing off the balance or making Hard and Easy mode difficult to balance. I’ve been using the bases of the class to scale the stats by the way if thats needed.
Any ideas?
I generally would try to work a lot with different Weapons. 2 Units that have around the same stats can feel widely different if one of them has a killer edge and the other an iron sword. Or maybe you have a relatively weak Lance soldier who is a pushover normally, but he’s positioned in such a way where it’s a bit hard to immediately kill him, and he has a lance which gives him extra damage per tile moved, so this lowly soldier instantly becomes more threatening through his weapon alone.
I saw your hack mention having loads of weapons. So you should have loads of versatility here.
Positioning is also important. Best Example: The Wyverns in FE12. On harder difficulties they have like 10 move, fly, good stats, and infinite 1-2 range breath that you can’t dodge. That by itself is really insane. But on top of that you fight them on maps where you have a hard time positioning yourself well, like in a desert, and on an open bridge with lava below, making fighting them that much harder.
Shadow Dragon often has cases where you sometimes wanna take a step back to lure the enemies in, so all your units can easily attack, compared to you rushing into the enemy with just a few units, and then facing the wrath of the other half of the enemies forces.
I personally always like to see promoted enemies early, so i would not shy away from that. The only thing that might be off could be the EXP gains, but as long as you don’t overdo it, it should be fine.
Worst case Scenario, if you notice nothing else works, and you have class slots you can use, you could also just duplicate the class and adjust it’s stat a little bit, then only give that class to the enemy.
Otherwise, more enemies on harder difficulties, maybe promoted ones where unpromoted ones used to be, and maybe the relatively generous time limit you have on easy and normal mode, becomes a bit more strict on hard mode.
Good example: There was a hack which had an escape sequence in a prison with 2 possible routes. However, since the big guy you were running from appeared a turn or two earlier on lunatic mode, you could not really take the quicker upper route unless you had a very strong and/or mobile team.
I’m unsure how FEBuilder handles everything, but iirc you can essentially make an event and have it change things like enemy weapons, or what reinforcements appear based on the difficulty.
The hack looks awesome btw. Can’t wait to try it out once it releases. I love Shadow Dragon and Ironmanability. 
Or manipulate character slots directly, given that you didn’t use the same slot for all of the fodder in a 12 chapter stretch ala FE7.
I especially like the idea of different types of named ‘title’ generics (Soldiers, Mercenaries, or different faction names) having slightly altered base stat lines to further differentiate, like maybe one region favors ‘iron defenses’ so all of their units tend to have 1 or 2 points more in general, or maybe the magic kingdom has more resist, bandits more health, that sort of thing, this also helps break up monotony and forces the player to consider different strategies, and making the player use a wider range of units means a harder game simply due to resource spread.
You could use this patch to bottom out the enemy’s hit rate.
NAME.en=Increase Enemy's hit rate(Editor)
INFO.en=Increases the hit rate when the enemy attacks.\r\nIf the hit rate is 30% and you specify 20 in this patch, the hit rate is 20+30 = 50%.\r\nThis patch corrects the enemy's hit rate for each map, enemy type, and difficulty level.
or
You can also make Arena harder to use.
NAME.en=Change multiplication rate of the Arena for each difficulty(install)
INFO.en=Change prize money of the Arena every difficulty level.\r\nBy default, it is 200% of the premium.(It will be twice the premium.)\r\nIf you set it to 100% of the premium, the money will not decrease.\r\nIf you set it to 50% of the premium, you will lose half of the money on your battle.