You can define a mixed behaviors scheme: 

You can have one workflow status where the All items are selected because you prefer that every one can attend a task and solve it (this is a free attention mode). Maybe your testing team work jointly, where one is the handler but every one can work on a task and move it to another state (for example send it to the development team because a bug has been detected). 

You can have another workflow status where the Handler items are selected because you prefer that only one (the handler) can attend a task and solve it (this is a restricted attention mode). Maybe in your development team the members work individually, and the handler of a task is the only one that can work on it, and the only one that can move it to another state (for example send it to the testing team when a bug was implemented and now the project has to be tested).