When is there reason to prefer "along with" over "alongside", or vice versa?
Received feedback, re a wedding invite:
Jane and Simon,
alongside Sam and Diane [i.e. Jane's parents],
cordially invite you ...
that it should be "along with". I thought these two phrases were interchangeable, and under the intentions of our copy (whimsical but adhering to standards) "alongside" seemed preferable.
I'd like to understand under what circumstances either choice is a better fit, and if my correspondent's advice is correct, how strictly it ought to be followed.
If it helps, my fiancée and I are American and everything is taking place in the US. Also the question is not about conventional wedding practices (that probably doesn't belong here at all), only the word usage.