I am having a small disagreement with my co-workers with respect to how to express that a question is being posed to a group of people.

In many internal documents I frequently see frases like this:
"Agents ask questions to all clients."

I disagree with this form as I don't think you ask questions to someone but rather of someone, or you pose questions to someone. I believe the sentence should read instead like this:

"Agents pose questions to all clients."
"Agents ask questions of all clients."

We are located in an area with a heavy Francophone population and I believe that the form in my first example is a borrowing from French where you can only "pose a question to someone" and there is no form for "ask a question."

Can someone confirm my analysis, please? Thank you.

Yep, I'm with you on this one.

"Ask a question to someone" is not a natural construction.

Actually, the most natural is with no preposition at all.

"Ask someone a question"

The next best is "Ask a question of someone"