Where did you see Philip Clover listed as Robert Smith's father? This is incorrect. I don't think you will find a primary source that states this.
If you only saw this in someone's Ancestry.com tree, then you are seeing a mistake. A possible source of confusion may be a DAR/SAR application. There are at least two SAR applications on Ancestry that include Robert Smith. These applications shift between maternal lines and paternal lines as needed to establish descent. They list the penultimate ancestral generation as Robert Smith Sr and Martha Clover, and the ultimate ancestral generation as Philip Clover and Mary Cooper. This means they trace their descent from Philip Clover, the veteran of the Revolutionary War, through Martha and Robert, not that Robert is a son of the Clovers.
You can never trust the trees posted on ancestry unless there is linked material to back it up. Many ancestry.com users are very careless with linking and adding relatives.