General change: Make Scrap Upgrades replacable. Like, if Drycha can somehow change the aspects on her tree units, it shouldn't be too difficult for a Warboss to tell his boyz to use different stuff. Also, it would be kind of neat if the character-specific Scrap Upgrades were actually unlocked through a skillpoint for each of the LL's, so they would remain obtainable after confederating them, kind of like how Thorek gets to unlock certain banner runes through his skilltree.
Some specific upgrades that should be changed:
1: Wizardly Weapons. It's just not very good and you are almost never better off using it over just Reinforced Weapons. Imo, they should imbue magic damage (and maybe some bonus melee attack) instead.
2: Immortulz Armour. It's described as bigger and harder armour. That doesn't make your more brave, it makes you more resilient. The only unit you'd ever use it on is the Black Orcs that also have the Immortulz Banner. Fear isn't that useful and extra Leadership isn't something you'd normally need on Black Orcs. This should have some kind of defensive perk instead. Extra armour, extra melee defence, physical resistance or a little ward save.
3: Scrap Barding. It's not entirely horrible, but why melee defence? It's armour, not some kind of combat training.
Stuff I would move around:
Goblins: Remove spiky weapons, add longer weapons. They are a spear unit, after all.
Feral Wyvern: Remove longer weapons, add scrap saddel
Stuff I would introduce:
Monster specific scrap upgrades. Why do monsters that clearly don't use any weapons have those? I'd rather have some that specifically upgrade the monsters themselves rather than some hypothetical weapons.
Goblin-supplemented diet. Sacrificing the occasional Goblin to protect the creature from the effects of starvation and the temptations of battlefield cannibalism has proven rather beneficial +20% Speed, +15 LD, +15% max health. Usable for: Arachnarok Spider, Lava Arachnarok Spider, Giant, Feral Hydra, Feral Wyvern.
Mushroom Brew. If itz gud enuff fer us ladz, itz gotta be gud for da Big Beastiez, too Frenzy. Usable for the same selection of Monsters as Goblin-Supplemented diet.
Shiny Rocks. Oi, deze are pretty! Gork'n'Mork iz gonna be 'appy if make dem idolz from those 20% Missile Resistance. Usable for Rogue Idolz.
Bigga Boulders. "Dis bad boi can throw 90 kg projectiles across 300 meterz." Anyone know wut dat's s'pposed to mean? +2 Detonation Radius, +20% explosion damage. Goblin Rock Lobbers as well as Da Big'Un Rogue Idol.
Kombat Drill. You gotta stab 'em smarta, not 'arda +7 MA, +7MD. Night Goblins, Night Goblin Fanatics, Nasty Skulkers, Goblin Wolf Riders, Forest Goblin Spider Riders.