You find the no longer Tercio statements often in modern books but a closer look into the contemporary German letters and texts by men on spot show that it is just half true. It was a mix of different formations.
The Imperialists used a modern form of “tercio” (a word that in Spanish originally means no special formation but just a third of the force – and allready in 1650 again just Regiment. With comtemporary men writing about a Tercio in tercio formation)
For example 1626 at Dessauer Elbbrücke Wallenstein had his men still 10 deep. Musketeers forming wings / sleeves but not with pikemen in these.
Even as late as 1648 the attack at Prague was done by a column formed by change from a “tercio” formation that had all pikemen together. Changing into storm column with all pikes at the front, followed by the shot. And no wings / hedges of musketeers.
It’s funny that modern authors ignore the contemporary textbooks that are written by soldiers. Not all old veterans but a lot still serving men.
So the 1625 Kriegsregeln by Meltzo. His formation is not as deep as the 16th century but still shows bastions of musketeers.
One can call the formations at Breitenfeld 1631 “tercios” or one might even state that the Spanish at Rocroi are no longer true “tercios”. Both is true and wrong. Tactic was fluent.
Does a “tercio” need four bastions of musketeers to be called so? No, many had just two wings and a small hegde in front.
The Lützen discussion about Imperial tercio or no tercio formation was caused by the dogmatic view that a tercio has to be as deep as wide.
That was not the case there. But the infantry acted like a tercio. Pikes in centre and the Muskets around.
The Swedish Brigade Formation with 1/3 placed before the “line” of the rest was not the tactical non plus ultra. In the last years of TYW it was rarely seen on continent.
But looks great like your top photo.
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