It's hard to know what it is about that picture you consider partial. Is it the triangular opening through which you can see the door? Or, more significantly in my opinion, the fact that the fly doesn't come down to the ground?
My tent is an Alpine Meadows. It looks like this:
(picture from a classified ad.)
I have been using it for over 30 years. We don't set it up facing into where we think the storm might come from, and about 20 years ago we added a vestibule on the front (but not the back) so we could have more room inside as our family grew. We have never had a "tent is flooding" rain problem - sometimes when we wake up we find a little water has come in, but not a lot. It's mostly through seams anyway because we forget to seam seal some years.
One year the kids were in separate tents and one of theirs flooded so much we had to bring her in with us, where it was dry. So I would not be too concerned that a tent like this can't stay dry.