Scorpion and Dante being balanced with +50% damage is an absurd thought. Scorpion in particular is already a monster held back mostly by limited DPS. With this, I'd actually bet a scorpion could probably solo a paladin.
Tremor with +50% DPS would be an absolute monster. It doesn't seem like much, but it's important to realize that the tremor does
obscene dps
anyway.
Single Hacksaw almost oneshotting a likho would also be absurd.
Going through more rationally:
Raiders: None of these could be buffed because they're already a menace to everything, including riots.
Riots: Absolutely not. For context, Mace would be doing almost 500 DPS. When a unit already has a ton of DPS, giving it increased DPS as a function of it's existing DPS is a recipe for disaster. Claymore
might not completely break everything on its own (Because it tends to overkill targets anyway), but claymore + 1 mace would just kill everything.
Assaults: Cyclops oneshotting thugs through their shields. Knights would be king of anti-heavy. Hermit does damage on par with bandit.
Skirms/Artillery: Ranged damage units are already strong due to preventing enemy interaction. Consider lance with a 30% faster cooldown and that's a good starting point.
The only things I can think of that wouldn't break the game outright (where +50% damage is a coherent concept) are impaler (since it can't hit moving targets anyway), limpet, and moderator (which tends to deal massive slow with limited damage *anyway*), and they'd still be oppressively powerful.
Anything past this is cheesing the question with starlight, ultimatum, etc.
None of these would actually be improvements. Balance can be pretty knife edge in zk, I think.