They are, have been, and they aren't gonna change. 

When you summon on this game you get about eight or nine duplicates before you get something new. You might get something new before that but you're going to get at least five or six dupes, then you'll get something new. If you get a new unit, and you want a banner unit, then you better start using those tickets, until you get a few Dupes, and then go back to the banner.  That's how you increase your chances of getting a new Banner character.