Yeah, so, rechecked and yes Nordland is the First Imperial Navy. Reikland's navy was old and leaky in the first place. Now, canon-wise out of respect to the Cult of Sigmar, Magnus apparently named Reikland's crap navy as the First Imperial Navy and named the more advanced and numerous and better maintained fleet of Marienburg as the Second Imperial Navy. And, eventually, after about a hundred years, and the Emperor at the time immediately post-Magnus was terribly impoverished with a very poor treasury.
And, apparently, canonically, the maintenance and building of new stuff for the Second Imperial Navy was levied upon the Emperor's treasury and not the province of Westerland at the time. And the Directorate offered to take all the fees and what not onto themselves, which the Emperor accepted, which relieved the burden on his treasury but effectively disconnected the Navy from him and then later the Directorate convinced the Emperor to let their personal merchant marine do the work instead of the Second Imperial Navy which was subsequently sold off piecemeal to wealthy merchants for themselves.
Then they seceded.
So...yeah.
And, apparently, canonically, the maintenance and building of new stuff for the Second Imperial Navy was levied upon the Emperor's treasury and not the province of Westerland at the time. And the Directorate offered to take all the fees and what not onto themselves, which the Emperor accepted, which relieved the burden on his treasury but effectively disconnected the Navy from him and then later the Directorate convinced the Emperor to let their personal merchant marine do the work instead of the Second Imperial Navy which was subsequently sold off piecemeal to wealthy merchants for themselves.
Then they seceded.
So...yeah.