Hello again,
You can use WBEM for Windows servers and ESX 5.x. But Linux ILO's and switches use SNMP so for your servers yes you can but for some Operating Systems and hardware you can't.
So if you install the WBEM agent you need to switch the datasource under setting in the SMH. You also need an account to configure SIm to be able to read the WBEM information. An admin account is handy to push these settings, you can configure a non admin to do the actual identification and datacollection. The non admin option is a repair option in SIM.
Does the SNMP 3th party tool need to send traps ? If you don't you can keep using SNMP, but no you can't parse the traps to either SIM or the 3th party tool.