The mechanic of the automaton was heavy customization. You had heads and frames. It wasnt beneficial to mix and match head/frame combos, except when they introduced the whm and blm heads.

Where the customization comes from are the attachments. Think of them as gear for your auto that either provides a stat boost or grants an ability.

Each attachment has a cost to equip based on the elements. Different heads/frames have different thresholds in each element. For instance, the soulsoother has 7 light threshhold but only like 3? In fire.

Not to mention just like player characters in ffxi the automaton has skills. However it's limited to melee, ranged, and magic skills. Automatons learn ws just like players, by reaching a certain skill level in ranged or melee skill. They automatically learn new spells by skilling up the magic skill, no scroll needed.

This is why i liked pup. Im not knocking bst or smn players but i didnt feel either has near the customization options as pup. Avatars and charmed/jug mobs just seemed expendable with no soul or personality.