If you mean Maxie vs Maxine, Maxie could certainly be a nickname. If you mean Harvel vs Harville you have to look at at least Harvel, Harvell, Harvil, Harvill, Harville and Harwell.I have seen a lot of known members of the family recorded or indexed as Harrell, Hartwell, Howell, Havell, Hawell and other challenges to reason.
There was a lot of debate a couple of years ago about some Georgia Harwell records that may actually be Haswell. Michael Flanagan almost had me convinced on it until I made a trip to Germany and had two different Germans clearly write out my name as "Haswell" in script after listening to the name being pronounced with my southern accent. I have decided it is not provable except possibly by DNA.
It is fairly easy to pick up variations when you look at printed matter with your own eyes but computer searches are tricky.
There IS material re Isham b 1789 on the Harwell, Harvell and Harvill boards which you should take a look at. Genforum no longer has the search all of Genforum feature so you have to look at all individual boards.
It appears there were other family branches in Hardin County who probably were not descended from Isham.