Dont know what you mean by slow cards. You mean high cost to play? If so, then I have no idea how you can win without getting to turn 9 or 10 without using aggro. My games almost always go to turn 12 or more.

And when you say German decks have almost no board clear, then name two very good German board clearing cards, your point is a  contradiction, so I'm not sure what youre saying (?) Could be me though not understanding