Your diagram and the sentence: 
[quote] 
"In terms of area it is similar to the difference between Micro Four Thirds 2x crop and Super 35mm 1.5x crop." 
 
[/quote] 
 
Is wrong. The C300 has a _larger_ sensor than the Black Magic. 
You're getting confused about resolution, sensor size and what 'crop' means. 
 
Similarly your resolution comparison is flawed - of course the Black Magic shows more details, you've effectively used a longer lens.