plague of Polish comics

To what extent are Asterix and Obelix an inspiration for Kajko and Kokosz? Is it possible to plagiarize oneself? When does inspiration end and copying begin? The problem of plagiarism is faced by various fields of creativity, so there is no way that comics can also remain free of it. Especially since in comics two fields of art meet: literature and painting, so the risk of plagiarism directly proportionally increases.