Don't believe anything Norwegian tells you.
I can't remember how many promises that have been broken in just the short time I have been here. Lies lies lies
Last winter 8 of us SH captains interviewed for RCA positions. Well, they failed all of us. Yes a 100% fail rate.
When asking for feedback, I was told that my SH personality didn't match that of a LH pilot. Who would known!
Point is, it doesn't matter what seniority you take with you to LH if they don't let you join in the first place.