User blog comment:Commisar Wadders/FEEL THE MIGHT OF BANEBLADE/@comment-1734134-20140127230311/@comment-2211810-20140128154938

And then the guardsmen and tech-priest are executed for doubting and attempting to replace the Emperor's holy tanks and their tried, tested, proven and trusted designs.

The tech-heresy that is your Tiger 2 could work for the SM or some of the Imperium's other elite forces (provided that there is an STC or other proof that the tank is rediscovered or intended tech that is Omnissiah-approved) because they're designed to put as much effectiveness and power as possible in small numbers, but for the Guard? Aww hell naw.

From a non-superstitious and non-religious standpoint, the main reason why the Leman Russ is still considered effective and widely-used is because it's practically easier to build and make spare parts for, and in turn, is easy to repair and modify. Few worlds in the Imperium are capable of making advanced components that would better suit a modern, slanted tank than a Sherman-like one, but all those primitive, underdeveloped worlds? They're better with making some of those flat, bolted armor pieces and bringing in some coal and firewood to the Guard, and then the Leman Russes are all armored and fueled up again.

Plus, most of the Imperium's enemies have anti-tank weapons that wouldn't give a single damn if a tank's armor is slanted/sloped or not. And as for the Leman Russ Tank's speed, it basically sacrifices that for the ability to better navigate rough terrain and steep cliffs. Heck, a Leman Russ Tank can even be modified to be amphibious, if need be.

Also, before anyone questions how poorly-protected are a Leman Russ Tank's crew, remember that anyone in the Guard is expendable, and thus, after the tech-priests and their assistants finish repairing the damage to a Leman Russ and adding in the spare components, they can just throw in another crew and be done with it.