powered through the use of an advanced internal combustion engine fueled with Infernium-9, which contains its own oxidizer and packs quite a lot of energy,
New tech
Rather like a hydrogen peroxide engine, which were in use in WWII, this is just an internal combustion engine which does not need oxygen from outside.
and packing a linked pair of remote-aimed
new tech
Seriously? You think an RC system is even meaningful? There were remote-controlled turrets on WWII bombers.
carefully re-engineered to be accurate even at Long rage,
Upgrade of an existing tech
And that's going to add how much difficulty, do you think?
with a highly reflective paint (In the laser wavelengths Ertex uses)
new tech
Nope, it's used on the Odins.
Heat sensors just under the ceramics detect laser shots and trigger a large array of smoke dischargers to fill the air around the tank with smoke (In atmosphere) or clouds of reflective metal chaff (In vacuum)
new tech
Heat sensors are pretty ridiculously easy, seeing as how they've been around for years IRL. Literally a bunch of digital thermometers programmed to go "Hey pop smoke over here" whenever the temperature rises too quickly to be natural.
A fire-control computer uses a broadband sensor package and a small radar set to calculate distances to targets.
New techs or miniaturization of existing ones
Miniaturization AND simplification, in fact, since the computer is working at shorter ranges. Oh, and all of this is stuff that's been in use since the 1990s.
Every vehicle from has a small IFF tag to allow the system to distinguish them from enemies.
new tech
This has literally been used IRL for DECADES.
The weapon is fully stabilized for fire-on-the-move capability.
new tech
This one was invented near the end of WWII.
It is entirely atmospherically sealed
Not exactly new but adds to complexity of the design
Not even remotely new, and everything else we have is sealed anyway. Not going to be a real problem, I should think.