PRO is delayed enough and PRE is ahead enough that they might be less than six months apart. Honestly this might turn into a Halifax/Vancouver situation at this point...
PRO also has way more first of class trials to do that PRE won't need to do.
The retain Asterix.campaign will fail based solely on crew availability. We have to stich together two tanker crews. That's going to be tight enough before we want to add a third.