As a native English speaker who studied German, Russian, and Polish, German was
much easier to learn than the Slavic languages. The case system is smaller than Russian or Polish, and there are far more cognates which makes learning vocabulary much easier. Also, articles (e.g., "a" and "the") are notoriously difficult for non-native speakers of English, but German is similar enough.
Learning cases is a little hard, and the silly capitalization rules are a hindrance, but probably the most difficult thing in German for most English speakers is waiting for the damn verb to make its appearance. It's harder to guess what it will be than it is for native German speakers.
I would guess that learning German would be easier than English for a native speaker of a Slavic language, though, precisely because syntax plays such a critical role in English, which has only the barest vestiges of a case system remaining. My Russian friends in particular make some amusing errors with word order sometimes, but I think it's charming.
Edit: and for the example given, "Man bites dog" and "Dog bites man," what is required is a verb change, perhaps a couple of articles, and correct capitalization (unless it's a news headline, in which case it's fine). So, "Dog bites Man" can be written as "The man was bitten by a dog" with the same meaning. English verbs are also hard for non-native speakers, though.