This is a great question! It's odd because I have never had to polish my Sterling CDC and it always looks gleamingly perfect! My other pieces-- SS Kelly Dog, Galop collection, etc. need to be polished as they do form a patina as well as tarnish. All are stored in the same way. So unless I'm wrong and someone knows better, I think that majority of H sterling pieces do in fact need to be polished.
My pieces have the opposite effect! My CDC develops a slight tarnish after a weeks, but the Galop GM is more resistant. The rest of my collection... really varies. But now I keep my silver in clear ziploc bags so I don't need to polish them often (or at all).
Tarnish really depends on many factors (how often you wear them, how it reacts to your skin, contact with water and perfume/skincare products, air quality, etc). I have heard that some pieces are plated with rhodium. Perhaps it's up to the particular workshop that produces a certain design.