Hi Patster and thanks for your inquiry. While we cannot provide medical advice over the internet (for your own safety), your concern does warrant a comment. In the most general of terms, it's always best when utilizing inhalers, to space their use and not to use one immediately after using another one. Of course, the best person to advise YOU on YOUR particular situation, is the physician who prescribed the medication for you in the first place. That would be my suggestion to you to have your question answered.
It's not safe or prudent to follow a physician's advice to another patient and use that advice as your own. There are countless safety issues that come into play in those circumstances.
I thought in view of your focus on Advair and Spiriva, that you might find it helpful to look over these two articles.
First, this one on Advair: https://copd.net/advair-diskus.
And second, this one on Spiriva: https://copd.net/medication-overview/medications/spiriva-respimat-spiriva-handihaler .
All the best,
Leon (site moderator)