Hah. They do pose some unique challenges for native English speakers. Can't say I've looked at Japanese but with Mandarin, there is (some) vocabulary that is slightly transparent, like 卡尔吗克思。 I remember really puzzling over that one in an article about an airport until I sounded it out. But you're right, the advantage for English speakers is significantly greater for Indo-European and especially Romance/Germanic languages.
(For anyone interested in the characters above)
If I'm right, they mean Karl Marx. In pinyin, Kǎ'ěr mǎkèsī.
I mean theoretically if a logographic orthography for western languages existed like it does for Japanese there would be no need for phonetic translation.