Slitherine

In the early period when the hoplites can be classified as armored is the thinking that all of the ones classified like that have bronze armor, or a large percentage, or what?

No, I think both bronze and laminated armour count armoured. The transition to protected corresponds to the period when armour of any sort became significantly rarer and many hoplites just wore what has been described as "a fetching off-the-shoulder number" (i.e. the exomis).