Whenever medieval combat is dicussed, people talking about it usually flung in to a rant about how on the battlefield "No Shield=Death." What about people who had two handed greatswords for example, or pole arms like halberd? Was their heavy armor enough to protect them against an arrow storm? How did they stay alive?
(I tried to find a question like mine in the FAQ, but i didn't menage to, so here it goes.)
This is a pretty short answer unfortunately as you hit it on the head. There's a reason that when shields began to fall out in favor armor inversely began to become far better as a whole. Knights and men at arms would almost wholly discard their shields or use significantly smaller ones like bucklers by the 14th century.
By the 15th century and into the 16th shields would mostly be utterly abandoned as armor did more than enough to ward off bullets let alone pesky arrows. There are even accounts in the 12th century of composite bows' arrows simply sticking out of the chest of knights as they marched on -- they simply lost their efficacy.
However the image of grand battles and the medieval Europe period, on average, do not align. There's a reason to say the least the 100 years war was literally 100 years with major engagements separated by decades. Intereuropean warfare of this period, and this would extend into the early modern period bar the 30 Years War (which was an exceptional exception to the rule of indecisive war; a trend which would continue immediately after for another 100+ years), was defined by raiding. Raiding and small skirmishes and siege warfare. Slow and methodical and notably not pitched combat of massive armies and thousands of archers.
Two principal sources are Western Warfare in the Age of the Crusades, 1000-1300 by John France and The Rise of Modern Warfare by H.W. Koch.
In general, shields were not necessarily needed to stop arrows, even if a metal curriass was not available. In his 15th century ordinances, King Louis XI of France instructs padded jacks to be made of at least 25-30 layers of cloth explaining that ". . . never have been seen half-a-dozen men killed by stabs or arrow wounds in such jacks, particularly if they be troops accustomed to fighting."
Alternatively, in eariler periods it was not uncommon to for soldiers armed with two-handed weapons to go into battle carrying a shield anyways. On the Bayeux Tapestry, one of the Saxons is shown holding off the Norman cavalry with a spear and shield while also carrying his two-handed greataxe in his left hand behind the shield.