I mean COME ON... The Ram has increased guardian armour and regen on hit! Essentially letting you be very very tanky. Now let's look at the "Insurmountable" Skullfort. Storm Fist KILLS regenerate health and you spawn with melee energy. It's clear that The Ram is more tanky. Despite the latter being for a armour specific class and the armour being considered invincible type.
I honestly think it'd be cool if hits increase guardian armour temporarily and kills regenerate health.