Pillars

Pillar: a supporting, integral or upstanding member or part. (Merriam-Webster).

From a child, I've heard the term pillar used to refer to those who provided support, often in a quiet and unassuming manner, and especially in the context of the church. It always struck me as a high compliment.

Some of the columns are in the sun; up front and visible.  Some stand in the shadows and carry their load unnoticed.  Removal of any one of them would put a greater load on the others.  And who knows how many could be removed before the structure would collapse.