No, it is absolutely not true. I would take a shield and single handed spear almost every single time. I've introduced this type of spear work to some of the best rapier fighters in the region. The spear, to them, is essentially an extremely long rapier with no hand guard. Their form is basically perfect, even though they were just recently introduced to the weapon. When they use a shield, we basically split 50/50 when sparring. When they use a double handed technique, I am winning 60/40. Part of that is that I am so out of shape. The other part is their extremely good technique, and their superb footwork. They are getting in fast, and when I advance, they retreat fast and efficiently, making me chase them. When I let them set their shot, they are simply faster and more accurate than me, regardless of whether it is single or double handed. When I attack first, or properly anticipate their shot, I have the advantage (until I overheat and run out of breath).
Against anyone else, I have the advantage, hands down. The shield is a major advantage. The only real advantage that a two handed technique has is the strength in a weapon beat or the bind, but that is poor tradeoff to the many benefits of the shield.
All through history, you see the spear/shield combo...for a reason. It only started to fall into decline with the proliferation of heavier armour and massed heavy polearms. Better to have a 10 ft axe and stand behind a line of men with shields, than to have a 7 ft spear with your own shield...at least in formation fighting. Remove the combo of shield wall, heavy armour, and long pole weapons, and the spear/shield combo is the winner in almost every battle not decided by cavalry or missile weapons.
And, the spear shield combo was still being used for dueling into the 17th C. The manuals from the Bolognese schools talk in depth about the use of partisan and rotella shield. It's just an effective combo, once you have a little training.
