This sounds like it could be the same guy. I don't really know for sure though. I have several (three actually) John Walker Howard's in my line.
The oldest was b. abt 1760 Maryland and married Margaret Stations
His son was John Walker Howard b. 1801 Mason County, KY and married Margaret Alexander
His son was John Walker Howard b. 1830 Ohio (I think) and married Suzannah Riggle.
So, which John Walker Howard is the father to Charles P. Howard? Probably the last one, I would think.
My line is actually John Walker Howard (the one b. 1830 and married to Margaret Alexander)...his son Richard Washington Howard. Richard Washington Howard had a son named Charles and someone thought this article related to my Charles. I figured Charles P. was a relation, but I wasn't sure what exactlly.
So, I have to dig up that article again...because I can't remember too much about it. I also don't have the youngest John Walker Howard's line complete (or I'm not sure if it's complete). I have his wife as Suzannah Riggle and they had a son Oscar.
Feel free to email me directly at firstname.lastname@example.org to explore this further. Thanks.