The Scorpion MBT isn't a character... It's also not impractical.
It has a higher profile due to the gun's elevation, but the hull height is standard. The turret is also much smaller and narrower in comparison to a traditional tank. This setup makes it great for hulling down.
Both the driver and gunner are protected by a solid plate of Titanium A armor.
The treads are setup for optimum all-terrain capability. The tank is designed for foreign worlds, but handles cities just fine.
- The armor is clearly not very thick if you can punch into the driver's cabin with a .50 rifle round. The original Halo left the driver
exposed.
- It has no coax gun (in the most recent iterations, anyways), and no 360 machine gun on the top, and instead has a
really big hole in the front of the tank's armor where they put a largely undefended machine gun with an extremely limited axis of fire. Never mind the safety issues involved with sitting right underneath the main cannon.
- The four mini-treads give it much higher ground pressure than a traditional setup, so it would easily damage pavement and get bogged-down offroad.
- It's absurdly slow. It has a max speed of 33mph (not that this can be accomplished in-game), which is significantly slower than an Abrams.
- A crew of two, a driver and a gunner, are expected to maneuver the vehicle, survey the battlefield, operate the main gun, operate coaxial and other secondary armaments (machine guns, grenade launchers, smoke grenades, etc.), operate various other systems, conduct field maintenance, and communicate and integrate movement with the rest of the tank platoon, supporting infantry, or other elements.
- It's very tall and very wide, which makes it a relatively easy target and hard to transport. And, despite being far bigger than a real-life Abrams, the cannon packs only a fraction of the firepower. Making things worse, the turret itself is so tiny that one wonders where they're storing the ammunition.
There is no plausible in-universe explanation for why the Scorpion is so terrible is that they spent several centuries fighting nothing but insurrectionist movements, and when they actually
did go to war it was against a military that manages to field even shittier tanks (seriously, Wraiths would get their asses kicked by WWII-era tanks), so they've never had the impetus to develop tanks to be anything other than cheap. But in that case, they'd have been better off just sticking with a 2014 design.