I think the Ext MVC pattern works okay, but it's not great.
Forcing controllers to use component query to wire up events means you can only do that for observable components, and have to wire up listeners by hand for other things.

Then there are some obvious holes; things that just don't fit, such as actions. We've taken the approach of putting actions into a sub-namespace under controllers, so something like Blah.controller.area.actions.Save, say.

If everyone knows what's going on though I believe everything is doable, and it should normally be obvious where the code for something is. If it's not you have to ask yourself if you're doing it right...