.

about forest knights-arquebusiers in heavy armor

Come to your senses.

They simply won't reach the archers, and they'll be completely crushed by pikemen.

The quote from the wiki speaks of unjustified losses without specifying the number. Plates won't be pierced by bows, either from a siege or at a distance; chainmail allows a deadly wound to be turned into a minor one, and the shield isn't worn as ballast. They will definitely reach them.

Imagine: you've lived in your village for thirty years, tilling the land. Somewhere far away, there's a war, and a knight, whose land you cultivate, takes you to it – he needs to bring a "spear" with him, a dozen or so armed men. You and a few of your fellow villagers are brought to a military camp, where you diligently swing pieces of wood, try to maintain formation, and learn to stick a spear into the ground to somehow resist the cavalry. After a couple of weeks, another journey. You arrive on the battlefield. You are told that the crowd of people in front of you, consisting of other peasants and their lords, are the enemy, and you are placed on the front line. Finally, you and a hundred unfortunate souls are charged by a solid wall of iron horses and men. If you managed to erase from your memory everything you've seen in video games and movies, and, in addition, you have a vivid imagination, don't forget to check your underwear.

Perhaps a couple of dozen knights will die if their horses are unlucky enough to run into spears firmly stuck in the ground that don't break or bend. But little will remain of the pikemen.

And again, there are other types of troops. Why send the most powerful part of your army to certain death? Which, moreover, has only one chance to attack, because the value of a knight bogged down in battle is much less.

Are we talking about heavy armor that cannot be pierced by arrows, or light chainmail?

Fabric padding + leather clothing + chainmail shirt, trousers, and hood + plate brigandine and a simple helmet with a nasal guard. The clothing weighs 25-30 kilograms. Just right for asserting your rights to the land of the Angles and Saxons.
Even two hundred years later, during the Battle on the Ice, full plate armor was still rarely used. The manufacturing technology was too complex.