You are probably correct in your assumptions.I noticed some discrepancies in one of Arvord's several years ago when I was entering the data into my database (with Arvord's permission).I told him about the mixup and he changed it in later editions.(Sorry - I don't remember the details - it WAS several years ago, and at least two hard drive crashes ago.)
Arvord was a researcher, but also relied on the work of other family members.
My online database was one of the first ones that contained the bulk of Arvord's work, and I am guilty of the middle 'A' as well.I will be correcting it in the next version that I am working on now.
I am indebted to Arvord for all of his work, and I hope that his memory will continue in our work.