you're missing a bit of realpolitik here.
Both the -B and -C are failing projects and will probably get cancelled due to the cost overruns and technical issues.
So it makes no difference which we order - it will get cancelled anyway. The only difference is that if we go with the -B, when that gets cancelled we won't have to pay for the catapults....
The ships will then just be mothballed and probably eventually flogged off to India