The Brandenburg class approached an all-big-gun idea too early

Would six identical 11-inch guns have made the Brandenburg class useful in the dreadnought era, and could the ships be refitted?

Uniform guns would make the design more coherent, but 16.5-knot speed and weak modernization margins still confine it mainly to useful Baltic service rather than front-line North Sea battle.

The Brandenburg class famously mixed 35- and 40-caliber 11-inch guns, so uniform weapons would improve fire control and design coherence. Even then, a speed of about 16.5 knots and limited protection would leave the ships behind modern battle fleets. Their most credible First World War use would be in the Baltic, while major refits could not cure the basic hull's age and constraints.