Just eyeballing it, the cuneiform looks like Old Persian, so not really appropriate for Gilgamesh & Enkidu to begin with. And Old Persian had a diagonal character to separate words, which I see just once here (and it's oriented the wrong way, though that's probably just a matter of the font used). So I tend to agree that it's gibberish.
Still, Old Persian is relatively easy to transcribe, so... Gilgamesh's second bubble (the shortest passage) reads 𐎲𐎺𐎥𐎼𐎿𐎭𐎹𐎼 ba-va-ga-ra-sa-da-ya-ra. Does this mean anything in any language? I'm guessing not, but anyone who wants to investigate further is welcome to do so.
The artist said that (in a self-reply on Twitter) aside from the German, the words don't have meaning. (Does the artist include the Japanese lines in that estimation? Curious...)
