Asian people, especially in business, will choose an Anglicized name for ease of communication with English-speaking counterparts. A name like ‘Susumu’ may be hard to pronounce when a non-Japanese speaker hears it or sees it written out, so Susumu may choose ‘Sam’. The familiarization of the name is actually used to convey approachability. ‘Danny’ sounds more friendly than just ‘Dan.’ ‘Johnny’ is less stodgy than ‘John.’ Plus, those familiarizations tend to be more common in the entertainment industry, which is generally where Asian people first hear of such names (Johnny Cash, Tony Bennett, Frank Sinatra, etc.) It’s not necessarily a pronunciation issue, but more of a ‘friendliness’ issue.