Keep in mind that Int guys only have 1 ranged weapon right now (junk turret) and only 1 melee weapon (stun baton). here those IdEas to help out
They need 2 more tiers for each type to balance them out among the other trees.
Chemical weapons: Able to craft special weapons that uses a "chemical" tier 1: thermite and willy pete.
Tier 2 Flamethrower.
Tier 3, Acidolator. (a makeshift gun that uses a special blend of chemicals( Rotten flesh , acid , Gas , Paint and oil) to make a Sticky and Acidic substance (like snowdog

) and it melts zombies by removing their limbs and acts like a gas that's in the air) (note, ammo is Hard to make) (also only can be made our bought not findable)
wasteland weapon's: Tier 1: Junk turret: a weapon good for defence and offence and with some mods able to shoot items like darts , arrow heads , Rocks , glass and more.
Tier 2, Blunderbuster or Dart-gun: Dart-gun shoots Darts and can go through a TON of zombies Max ammo 10, Blunderbuster can fire 2 shots at a time. (max 4 shots) and it can use Blunderbuss ammo or shotgun shells and can turn zeds to red mist.
Tier 3: Railgun: this Makeshift gun uses Air Pressure and electricity to Propel a pellet at a super speed, (has small chance for shock damage) and can hit like a truck when fully charged (like a bow but slower) and can Go through zeds like nothing! (note: Hard to make. cant find! only buy or make!
And Melee science!
Tier 1: shock baton
tier 2: Piston Gauntlet: Basically this uses Pistons , Compressed air , springs and more to make a gauntlet that can Make the best brawers jealous, able to Punch a zombie and they get Knocked back due to the force of the Hit. (note: need a lot of parts)
tier 3: Chain-axe: basicly the Auto axe from fallout 3. while not good for chopping wood, its great for armor and Flesh able to tear threw them dead bois "like a beaver threw a rotten tree"
and the Junkturret Parts and stun baton parts can me "makeshift Weapon parts"