If you want to have a series within an opening dependent clause, how should it be punctuated?

Question

Perhaps it is because of my computer programming background, but it seems to me that there should be no internal commas in opening dependent clauses.

The following sentence is a relatively simple example:

When Sarah, Bob, and Frank try to work together, they always seem to argue.

This sentence is easy to understand, but it just feels odd to me to have one or more commas before the comma that ends the dependent clause.

Perhaps the following example is complex enough to illustrate the problem more fully:

If she has had the account for more than two years, her account balance is greater than $500, and she has never had any overdraft charges applied to her account, then she qualifies for the rewards program.

Obviously, both these sentences could easily be reworded to avoid this problem. In these instances, it would be as simple as moving the dependent clauses to the ends of the sentences, but are they correct as they are? I tend to avoid this construction whenever possible, but it is sometimes the most natural and most easily understood way of expressing the thought, especially when complex conditions must be addressed and understood by the reader before the consequences of those conditions can be fully explained.

I can’t seem to find any authoritative information about this construction even though I have researched it quite a bit. Should such sentences always be reworded? Are the example sentences correct as I have written them? Should semicolons replace the commas at the end of the dependent clauses? It seems strange to use a semicolon in this situation, although that is exactly what is done to avoid ambiguity in the similar situation of a list in which internal commas appear.

Any opinions, especially ones from style guides or other authoritative sources, would be greatly appreciated.

Answer 1

They are fine as is. There is no ambiguity. They are correct grammatically, punctuated well, and semantically clear. Don't worry about it.

But, if you can come up with an example that is so long, or so convoluted, or so ambiguous or confusing, that commas don't seem to do the job; use a semicolon, per CMS, as DeadRat suggested.

Answer 2

There are no "authoritative" sources for this kind of thing. Obey your manual of style, either the one you pick or the one thrust upon you. The Chicago Manual of Style recommends that

[i]f the clauses of a compound sentence are very long or are themselves subdivided by commas, a semicolon may be used between them even if they are joined by a conjunction.