Hi @Ashish Sharma and @CyrilAzoulay,
Short answer to accomplish the requirement is install log analytics agents on the VMs and get the CPU Utilization % for VMs in single request through API by leveraging this and this API reference.
Sample kusto query to use in this or this API:
Perf
| where CounterName == @"% Processor Time"
| where ( InstanceName == "_Total" )
| summarize AggregatedValue= avg(CounterValue) by Computer, bin(TimeGenerated, 30s)
Here is the related detailed explanation w.r.t it.