Currently process \ disk monitoring rules are mutually exclusive, means only one rule must be configured against a model. If there are two rules applied, then the alert appears, which sounds like "conflicting rules".
This is not handy, as rules are applied to collections which are usually NOT mutually exclusive, for example, [all windows] and [windows 2008].
If i want to apply different rules for [windows] and [windows 2008], then i need to create an awkward subtracted collecction [all windows but not 2008], which is obviously not a nice way.
I suggest to add a custom parameter to rules - a priority. In case of clash, highest win.
Mind the fact that you already use priority in a particular case - for local rules. If there is a clash of local rule and a global rule, then local wins. Just expand such "priority compare" behavior to global rules relations.