According to the substitution code you posted, that doesn't say "sunrtusa" (anagram for Saturnus), it says "sunrdusa" which could just as easily mean "Surandus" (ancient musical instruments) or "Sudranus" or "sud Urans" (south Urans) or "sud ranus" (south Ranus) or "sun radus" or "sun duras" (harsh sun) or "sundrasu" (disintegrate).
When you apply a substitution code to a word here or there that doesn't work for the rest of the text, then you have to ask yourself whether the similarity to recognizable words is coincidental or due to the basic similarity of vowel-consonant balance in most languages.
When you apply a substitution code to a word here or there that doesn't work for the rest of the text, then you have to ask yourself whether the similarity to recognizable words is coincidental or due to the basic similarity of vowel-consonant balance in most languages.