"The sheer bulk and size of the spear required the soldiers to wield the spear with both hands, allowing them to carry only a 24 inch shield (pelta) suspended from the neck to cover the left shoulder."
Exactly my point still stands. They used those with both hands, not one hand & one with a shield.
Read history, but don't just skim the fighting style. There is a big difference between a 10 foot spear with a punch shield, a 12 foot spear with arm straps, and a 15+ foot spear that is used with 2 hands.