I've got a bunch of solar on our boat (3x120w & 2x50w). I considered putting some of these in series like you did so I could safely reduce the wire size back to the controller, but chode not to since a shadow on a single panel would then affect the output of any panels wired in series with it.

I dunno if shadows are a big issue on your cat, but on my monohull (Kelly-Peterson 44). they are a huge issue, especially while underway.