re: Phoenix
So, what if The Great Bombardment ALONG with Mars's demise of it's dynamo gave rise to it's demise. That doesn't mean that there was no running water, no rain even while the great volcanoes on Mars were active. It could and does mean so far that Mars had running water mixed with sulfuric acid/solvents at one time. At some places more than others water could have saved the day enough to have given rise to microbial life or life for that matter, we still do not know.
We still do not know. Bottom line.