Ah, ok then, you’ll want to count the unique instances of each applicationPool using ‘multiplicity of’ the unique values as @brolly33 mentions.
q: (multiplicity of it, it) of unique values of node values of xpaths "//@applicationPool" of xml documents of files "applicationHost.config" of folders "inetsrv\config" of native system folder
A: 1, CCM Client Deployment Pool
A: 1, CCM Client Notification Proxy Pool
A: 1, CCM Security Token Service Pool
A: 3, CCM Server Framework Pool
A: 1, CCM User Service Pool
A: 1, CCM Windows Auth Server Framework Pool
A: 1, CCM Windows Auth User Service Pool
A: 1, DefaultAppPool
A: 2, SMS Distribution Points Pool
A: 1, SMS Management Point Pool
A: 1, SMS Windows Auth Management Point Pool
A: 8, WsusPool
T: 73.260 ms
Or, to return only your noncompliant/duplicated ones:
q: (multiplicity of it, it) of unique values whose (multiplicity of it > 1) of node values of xpaths "//@applicationPool" of xml documents of files "applicationHost.config" of folders "inetsrv\config" of native system folder
A: 3, CCM Server Framework Pool
A: 2, SMS Distribution Points Pool
A: 8, WsusPool
T: 85.024 ms