How much hull change would six 18-inch guns require?

Would a Queen Elizabeth-based ship need a much longer or wider hull to carry six 18-inch guns?

Only modest adjustment in this reconstruction, chiefly moving the two forward turrets, superstructure, and after turret closer to the ship's center.

Deleting one of Queen Elizabeth's four twin mountings creates room for three larger twin turrets without demanding an entirely new outer hull. The heavier barbettes and magazines still require the remaining mountings to move inward. In this reconstruction, the forward group shifts aft, the superstructure moves with it, and the after turret comes forward. The six-gun Agincourt hypothesis is physically plausible while remaining unproven as an Admiralty intention.