Well, you also have to remember that the Garleans also built the magitek armour for a specific purpose -a form of armoured transportation. To them, it's basically little more than a single seat walking tank - it's the Garleans' 'steeds' used by their cavalry (like in Eorzea, they'd use mounted soldiers on chocobos, like what the player has).

Having said that, it's clear that Garlemald does in fact know about automation technology - the FFXIV website itself all but screams that fact in it's description of the magitek vanguards, stating that they're autonomous, meaning they probably run according to some rudimentary artificial intelligence, not too dissimilar to the mammets found in Eorzea (although considerably more advanced of course).