IOWAIT and CPU usage

Hi, I am new to promql, I am planning to monitor about 100 servers in a panel for IOWAIT monitoring and other one is for Avg CPU Usage.

Below are the expressions i am using, However i see quite different number’s on physical servers using commands(sar, iowait, iostat). each server has 16 CPU cores.

For Panel IOWAIT
(avg by (instance) (irate(node_cpu_seconds_total{job=“node_eporter”,mode=“iowait”}[1m]))) * 100

Panel Avg CPU Usage
(1 - avg(rate(node_cpu_seconds_total{mode=“idle”}[5m])) by (instance)) * 100

Can someone please correct the expressions i am using, and help me understanding this
Note: Each server has 16 cores(cpu0,cpu1, cpu2…etc)