Hi,
When you create your Posture Policy, create 3 different rules and for each rule use "Other conditions" from there you can use different attributes to determine the source of the connection. E.g. If you use Network Device Groups to group Switches, WLC and VPN Firewalls use the "DEVICE Type EQUALS All Device Types#Firewalls" create another rule for switches and another for WLC, make sure the "Other Conditions" attribute uniquely identifies the different devices. Then apply the requirements for that network access connection type.
HTH