Out Like a Lion Lyrics

Lyric discussion by SirenAsunder 

Cover art for Out Like a Lion lyrics by Whitehorse

I am so enchanted with this song, but I'm still trying to parse it after four or five years. Here is all I've got so far:

In-like-lamb/out-like-lion obviously refers to March, and seemingly means someone presenting as innocent in the beginning, and then later revealing themselves to be some kind ferocious.

The Mary Rose was a navy warship during the reign of Henry VIII, which sunk in battle. More in-like-a-lion and out-like-a-lamb, that -- am I wrong?

The rest of the lyrics, I'm still unwrapping. It sounds like a postmortem of a relationship at a particular time of year.