Marioz,
Schwinn seems to be playing the name-game with their bikes. A fellow recently posted a picture of a bike he bought at a big box store in Minnesota. It was called a Southport and looked exactly like a Jaguar only it comes in Black & Cream instead of the Jag metallic blue. I've not seen the Landmark but I'd bet you're right; it's the same bike just different decals and paint. I want to research it a little, maybe I can get some answers for us.
Tom