Hi,
I had a 2006 Mini Cooper S (pre-kids!) Having the smaller speedo and tach side-by-side above the steering column was an option on the early BMW Minis. It was called the 'chrono pack' and replaced the large centre speedo with a few small gauges. Was not an option on the second generation I don't think.
So nothing to do with line of sight, but I preferred it because the smaller speedo was easier to keep and eye on, and my right foot is heavier than my left!
Tone