'From what I understand, we were supposed to have three of these to enable'
I've never seen that mentioned anywhere before, one of the planning assumptions* was that the design would learn from commercial practice where their ships don't spend comically long periods of time alongside doing basic maintenance. Consequently to guarantee availability of at least 1 hull at sea for x days per year you only needed two ships, similar to how the River class patrol boats are operated. Of course there was also an assumption it would need to be ~60000 tonnes to embark an air group big enough to carry out x sorties a day with y aircraft so I'm not saying that plan will actually work out.
*Somewhere I have a couple of copies of the RN Engineering Review which have articles about the design process. This may well prove everything I say to be a lie based on poor recollection.
Biting the hand that feeds IT
