NCL is currently 2 A319 AND 1 320.
Mixed fleets will hurt the ecomics of the smaller bases. GLA, PMI, BCN, VCE , NCL etc. Having a small sub fleet in LGW is one thing. Having a third or quarter of the fleet a different type pet base is different.
The larger bases should be A321/A320 IN 186Y should be the way forward.
I do think the Bombardier thing is just being hospitable to them and will use to negotiate with AB in future.