Well, yeah, there are holes in my plans if you believe that what I dish out is the only final product I'm advocating. But, with a little modification these things can be taken into account.

For example, with what you said, Tribunal's power may be affected by having their Scales or not, and the fetish or not, but it could also be affected by other things, such as:
(a) if the number of flags placed is close to the number of attacks by non-Tribunal/Deputies in the city;
(b) higher number of criminals killed (can up their power considerably compared to the rest);
(c) number of persons killed by criminals within a protected city; or
(d) hours that criminals have spent in protected cities.

If criminals are dying left and right, nonexistant, flags are being placed for most attacks, or the criminals are at least kept out of the cities, and if the fetish is taken, the Tribunals should be pretty powerful.

Maybe Tribunals have more guards on other roads when their fetish is taken and to piss off their normal friend, Empire, Centurions no longer can be called on roads? Or, they can do that teleporty-thingy to Arkham and call guards works in Arkham? Balator as well, and it can no longer can support Centurions? This could irritate Empire. Sorta hard to figure out an anti-Fortress Tribunal buff, but I bet it could be done.

Also, depending on to where a cabal focuses any new strength could define some leaders' reign by choices he/she makes.

Anyways, more thoughts..