However, it may also be because in western countries the team of translators is more critical and knowledgeable (with regard to the greek or hebrew language) in their approach to translation. There may be a huge "need for clarification" with Warwick for these countries - which takes a long time.
I know, for example, that in the european branch office (in Selters Germany) german JWs with greek mother tongue knowledge are working on the translation.
jmy2c - I don't know what it's really about.