List Virtual servers that are offline for past 90 days

I took take a different approach. Since it seems you don't have this information in your SIEM, you could generate it locally. I had a couple of scripts doing this:

1. Have a script to find all pools with Active Members 0
2. Run the same script 90 days later
3. Make a diff
4. Have a second script search for all virtuals with these pools attached.
5. Make an SCF of these virtuals and pools... just in case you plan to delete them and you might have to return them.

Unfortunately the script was written in my pre-Git time and also at my previous employer, so it's not available for sharing. But it was a simple bash script with a bit of sed and awk.