Sizing a mixed broadside and central-battery ironclad

How long would a hypothetical ironclad combining broadside and central-battery arrangements need to be?

Roughly 100 to 105 metres, using an Audacious-class ironclad as the comparison.

The proposed ship combines a central battery with a broadside arrangement inspired by Warrior. Its broadside section would contain at least six guns, preferably eight. An Audacious-class ironclad provides a rough comparison, with some allowance for a larger hull. The resulting estimate of approximately 100 to 105 metres supplies a general scale for the proposal, without a detailed hull design.