Why the Oregon City cruisers became a new class

Why were the Oregon City cruisers treated as a new class rather than another Baltimore batch?

A new designation helped attract funding support and justify cost, while the cruisers also incorporated internal changes from the Baltimore design.

A proposed explanation for the Oregon City designation combines funding arguments with design changes. Calling it a new class could attract political allies in Oregon and help justify a higher cost than another Baltimore batch. The cruisers also differed internally and addressed Baltimore shortcomings. Their classification therefore had both an institutional and a technical rationale in this interpretation.