Resizing images of different sizes to one size can be a challenge. You can do it in a couple of actions. First resize the width to 800 with one action. Then take the resulting folder and do a second action. The second action would be a canvas resize. Resize canvas height to minimum height of the images from the first action (533 in your sample of those 2) with anchor in center. This will crop the top and bottom of images.

It can be done the other way around. Resizing the image height then resizing canvas width.

Either way there would have to be some cropping. In that example there would be a 33 and 34px (67px divided by 2) crop on top/bottom or left/right side.