[anonymfus]

First, that is not because of writing system specifically, but because of the rhythmic structure of Japanese language, see, for example, this video:

https://www.youtube.com/watch?v=J_HLY0Rss-g

Second, in Japanese dubs these words are not usually actual English words, but Japanese words originated as borrowings from English language, so voice actors don't actually mangle them, the same way as English speaking people don't mangle the word "coffee" as they usually pronounce it, despite it being different from how Italians pronounce "caffè".