Is it really guaranteed that an higher salience rule will fire before an lower one? Does anyone had any problem with that?

The docs says:

The most visible one is "salience" or priority, in which case a user can specify that a certain rule has a higher priority (by giving it a higher number) than other rules. In that case, the higher salience rule will always be preferred"

I have to simulate a sort of activation group where the rules in the group can only fire exclusively per object and does not influence firing rules outside the group. I am using salience as part of the solution.