There are insufficient three car 331s even today, with various pieces of EMU work in the Liverpool area still withdrawn, for the Manchester Airport or Hazel Grove to Blackpool North services to all be diagrammed with pairs.
The Manchester Victoria - Preston units will be released.
It seems likely that at least one more electric unit than today will be needed to provide separate Hazel Grove diagrams, which could be a four car if available, or a pair of three car 331s if not.
So however you look at it it's very unlikely that there are enough 331s to cover 2tph Manchester Airport - Blackpool North in pairs.
However, with a small amount of work at Layton and Adlington (Lancs), and a more significant amount of work at Leyland, and putting all of the calls at Salwick back into the South Fylde, pairs of 323s would be feasible.
Regarding the Cumbria services, the net provision of three two car 195 diagrams and a driver for shunting might be all that'd be necessary for these to run as five car between Manchester Airport and Preston.
I also note that the incoming fleet would hint at a small surplus of two car class 156 and three car class 323.