Panel interviews can be incredibly stressful and certainly from the ones I've been involved with not everyone needed to be there.

Often I think it's the case that higher-ups can become offended if they're not invited to be on the panel - particularly in academia!

As always, your mileage may vary, if you want (or need) the job then plug away and remember that not everyone on the panel will have a clue what you're talking about anyway...