You can't just find a similar-looking name in the past and assume it is the origin of a modern name without providing the links that show how the two are related. Unless you can trace the use of Simaetha down the centuries and show how it changed into
Samantha, this is just a hypothesis without real evidence.
This is not to say this hypothesis can't be correct; just that pointing out the use of Simaetha in
Aristophanes' play is no proof there's any connection between it and
Samantha.