Let's say there are three people, Bob, John and Jane. There are also three languages, L1, L2 and L3.
John is a fluent speaker of L1 and L2. Jane is a fluent speaker of L2 and L3.
Bob only knows L1, but wants to learn L3.
John, to help his friend Bob, translates a list of vocabulary from L1 to L2. Then he passes it on to Jane, who translates the words from L2 to L3. Thus, Bob has a dictionary of words between L1 and L3, as a tool for learning L3.
The question is, given any set of three languages, is there likely to be significant "telephone game" or "chinese whispers" effect by doing this? Does Bob risk learning inaccurate or plain wrong definitions of words by working this way? Are there any good examples of this? Would this depend any on the language families of L1, L2 and L3? Would this be more, or less, complicated with full sentences, than with loose words?