Very interesting question, and it is indeed possible, But as a first step you would a calculated field that decodes the values or serves as a bridge between the both?

Case SourceA

WHEN 'Virginia' then 'VA'

WHEN 'Maryland' then 'MD'

WHEN 'Newyork' then 'NY'

END

Or decode into a common integer if you prefer.

End of the day, the columns/fields need to match at ASCII level, to be able to pull in those records.