Linothorax vs Spolas

[Dan Howard]

Personally, I know of no evidence to support the use of linen for armor

As already said, there is plenty of evidence of layered linen armour. In Medieval Europe it was called a padded jack. It was quilted not glued. All types of layered textile armour from Europe, Asia, Middle East, India, Russia, America, etc, etc, are quilted. The "glued linen" theory is complete bollocks IMO. There isn't a single example from anywhere in the world in four thousand years of military history.

It would seem counter-productive to use linen when leather is so much more resilient, available and economical.

Williams conducted tests of both quilted linen and hardened leather and concluded that linen provided far better protection against blade edges and points.
See The Knight and the Blast Furnace.

I don't know about Greece but in Western Europe leather was more expensive than linen and leather armour was mainly used in tournaments while linen was used in battle. The further east you look, the more common leather armour becomes. By far the most common form of leather armour is scale/lamellar, not a solid cuirass.