You forgot to count in the two types of masculine gender. ;) :D

Yeah german declension is way easier. Our genders are more obvious as well as which paradigm to use. PS: sarkasm :D

By the way, here are two ways to say "the pot calling the kettle black" in Czech:

Zloděj křičí, chyťte zloděje (literally "a thief shouts: 'catch the thief!' ")

Hrnec kotel kárá, černí jsou oba (literally "the pot reprimands the kettle, (but) both are black")

It would either be "German isn't easy at all" or "The German language isn't easy at all." It just sounds wrong without the article.

"German language is not easy at all." is accepted.