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.