Yes, they are only hilarious. Švejk on the other hand is in my opinion much more serious. One Czech literary critic call it even “Kafka by other means”. Yes, Hašek was a satiric writer, so that’s how he wrote, but Švejk is IMHO actually a serious book about the horror of a human being liquidated by the impersonal power of modern society.
There was a recent collection of new translations of his stories, many of which had never previously appeared in English. They’re not ideal in that the translations are translations of a German edition of his stories and not the original Czech texts, but they’re still a fun read.