Not sure I 100% follow what you trying to do, but you may have better luck if you try fiddling with the crop position. But it’s odd you are saying cropping from the top left, as default crop position is center and center.
add_image_size( 'featured-image-2', 640, 200, array( 'center', 'bottom' ) ); // Hard crop center bottom
The first value in the array is the x axis crop position, and the second is the y axis crop position.
- x_crop_position accepts ‘left’ ‘center’, or ‘right’.
- y_crop_position accepts ‘top’, ‘center’, or ‘bottom’.