Ok, the argument regarding the Brandenburg class is this: What distinguishes the Dreadnought type from a pre-Dreadnought? As I understand it from the article the only requirement is the uniform main battery in bore diameter and barrel length. There is a whole list what the advantages are and the only ones the Brandenburg class did not meet due to the different barrel length is maximum range (the difference is nearly irrelevant in 1890 due to fire control abilities) muzzle velocity and thus flight time and splash distinction (irrelevant because of the low number of differing guns and the missing central fire control at this time). Dreadnought labeled ships had 6 inch guns as secondary armament while the Brandenburg had only 4 inch ones as next biggest after the main guns. The maximization of striking power on long range has to be seen in the context of the time, the long range is the maximum of guns and fire control, also the power of HE does not depend on muzzle velocity but on caliber (as used in the article, which was the same for all of the 6 guns) and even the Japanese used HE 15 years later with their big guns...
The other advantages of the armament rest on "caliber" as used in the article (see "#Main armament power and caliber"), not on barrel length, like logistical simplicity. The fire control advantage from splashes is there for only 6 guns, and if 2 shells arrive even a bit later, it is even better for distinguishing shots with the non-central firecontrol in use at this time. The rate of fire was uniform and about 2 shells per minute as stated in the Brandenburg article, no problem there as well.
What about the rest of the design features of Dreadnought according to the article? Central fire control was not implemented in all the "Dreadnought types" and if it was used, then to very different degrees. The position of the main armament on the Dreadnought itself was not optimal with the wing turrets, the Brandenburg was more advanced with only centerline turrets. That there were problems like the blast damage was not uncommen, Dreadnought ships had wet guns and so on as well. The armor was undergoing heavy changes before and after the Dreadnought, the Brandenburg class had composite armour, the all-or-nothing scheme came later than Dreadnought and the armor deck (plunging fire) was thicker on Brandenburg than on the Dreadnought 15 years later. The turbine was not used by early US Dreadnoughts and coal was used on much later British ships.
Interesting how ships not even having the same caliber (as in the article without barrel length) are mentioned as being semi-dreadnoughts and the Brandenburg class 15 years earlier only lacking the uniform barrel length but coming much closer to the "Dreadnought description" in many other aspects than actual early Dreadnought is totally omitted...