"Oh and Sh guys also have a union" - "There is talk about a union"
Doesn't the LGW based, agency contract contain the clause "no claim as employee of the airline" - or similar?
Such a clause would prevent the formation of a legally recognized union as there is no direct employment relationship between the pilots and Norwegian.
If you recall, the main reason for the recent strike was for Norwegian to be the named employer, with whom a "union" has legally binding, collective bargaining rights.
Perhaps the term "pilot association" is more applicable (with no legal rights whatsoever).