Why the Deutschland design made limited strategic sense

Was the Deutschland class best understood as a fast cruiser or a pocket battleship?

It was a constraint-driven German compromise whose logic did not translate well into a generally useful warship type.

The ships were conceived while Germany was replacing obsolete pre-dreadnoughts under tight constraints. That context made the otherwise unusual large-gun cruiser idea more understandable for Germany. Even there, the compromise is judged only marginally sensible. Its logic should not be generalized into a superior cruiser or battleship formula.