>>96359912
One thing the other anons didn't mention is that at this point of the setting Armageddon was still called Ullanor and although the orks had been cleared out the imperium hadn't settled the world yet.
Armageddon doesn't get settled by the imperium until after the War of the beast ends when the Admech fuck around with imperial records to hide the location of Ullanor so they can steal the planet and study all the proto krork tech left behind.
No armageddon means no armageddon pattern. That said the picture you posted looks like it has the same sealed crew compartment as every other Sol Aux tank so you could just, call it a Voss or Metallica pattern if you wanted. Its not as if EVERY auxilia Cohort would be exclusively using Mars and Saturnyne pattern equipment.