50% higher bit rate vs 20% higher resolution
Could you give files (or png screenshots) to comparing?
I think that file with higher bitrate and higher resolution should look better, with other conditions being equal.

1056*594 = 627 264 pixels.
1280*720 = 921 600 pixels (47% more pixels relative to 1056x594 resolution)
921 600 / 627 264 = 1.469 * 100% = 147% relative to 1056x594 resolution.

2966 kbps for 1056x594 - 43% more bitrate for this video, relative to 1280x720
2073 kbps for 1280x720
2966 / 2073 = 1.43 * 100% = 143% relative to bitrate of 1280x720 video.

What do you think?
I think that with these settings both videos should be approx equals. Maybe the subjectivity of the perception of the human view will make its adjustments in this comparing.