MOh
I suspect it's more to do with dicking about with the programme at this late stage, particularly when you've just spent a year putting together a JV (under threat from MinDP) based on certain workload assumptions.
The french yard you are assuming (although it could be DCN instead) built nothing for over two years after QM2 and is now owned by Aker (which is a good thing in efficiency terms). Stephen is far too sensible to get involved with an organisation (DPA) that struggles to know what it is doing.
I do not dispute that we are currently paying way over the odds for the ships and that is directly down to the inability of PFG (despite their best efforts) to provide good technical cost estimates on an activity basis and use them to batter both corporate BAES and the Clyde SB lobby. Nevertheless, as you say, any more delay will inevitably escalate cost.