The fast task groups created by completing the Lexingtons

What changes if Lexington and Saratoga are completed as battlecruisers rather than carriers?

Later Lexington hulls become the carriers, producing fast groups that pair one carrier with one battlecruiser.

The slow Colorado class would not replace the carriers lost in this counterfactual. The next two Lexington-class hulls would instead become the treaty conversions. The United States could then pair each carrier with a fast Lexington or Saratoga battlecruiser. That combination creates two powerful mobile task groups and gives the Royal Navy a new force-development problem.