I was gonna give you bullshit for making it amphibious while also being on a "lightweight frame based on the Tiger truck" but the dice have smiled on your today.
Hard: 6
UF-MLRS-44 "Artemis": The Artemis is a mobile rocket launcher, on an amphibious truck chassis. The truck itself slightly resembles a Salamander, but lacking armor, with the same hexagonal cabin, but which cuts short for a bed. The motor is directly below the cabin, between the front two steering wheels, and powers four drive wheels and two small propellers towards the rear. The wheels have large, wide tires and sit on portal axles for clearance. The weapon system sits in the bed of the truck, and consists of a 4x10 array of 40 rocket tubes. In each rocket tube is a 120mm rocket, 3 meters in length, which rotates 360 degrees and elevates to 90 degrees (which is used for the reload process) under hydraulic power from the motor while the vehicle is deployed. The fin-stabilized rockets are accurate to 12km, and at can be fired to 15km at maximum. Each carries a 20kg warhead, comparable to a much wider artillery shell, and weighs 60kg in total with its body and solid propellant. The missiles are reloaded an entire rack at a time, while the aiming apparatus is in full vertical position, from a second truck with a hoist. To reload or fire, the Artemis must deploy stabilizers which takes about 90 seconds, and the same time to prepare to move again. Lastly it has a device called an "air conditioner" which somehow makes cold air inside the cabin through some pressure valve parlor trick, which the crews are absolutely in love with despite its lack of specific combat value. [4 Ore 4 Oil]