I've just been having a look at them as I tried to design my own rules to accomplish what you wanted. Having had a reasonable stab at it I decided they were about as inelegant as an inelegant thing could be.
So I looked up WBH rules to see what they'd done. Here they are:
p.78
///quote
Roll 1D-1 to determine the number of major governmental powers on the world. Distribute the world's population UWP among the various governments.
Next, roll 2D-7+(world population UWP-1) to determine the local government type of each rival government. Ignore and reroll a result of 7.
Finally, roll 2D-7+local government type to determine the law level of each rival government.
Treat each rival government as an independent world government when using these rules to detail a government. Therefore, follow the rules in this section *for each government* to arrive at its detailed organization.
Example: A balkanized world has a population of 75,400,000. Rolling 1D-1 yields 5, giving us five major rival governments on the world. We arbitrarily distribute the population between them as follows: 1) 40 million, 2) 15 million, 3) 10 million, 4) 7 million, 5) 3 million.
Rolling for each rival government's type we get: 1) a 5 gov type, 2) a 5 gov type, 3) a 4 gov type, 4) a 3 gov type, and 5) a B government type.
Rolling for each rival government's law level we get: 1) a 9 law level, 2) an 8 law level, 3) a 3 law level, 4) a 7 law level, and 5) an E law level.
///end quote
I like the simplicity of this - although it doesn't quite do what you want it to WRT to GOV and LAW being affected by one another (or TL for that matter).
I like that it says 'major' powers so you always have the option of lots of minor ones if you wish.
Not so fond of it only allowing 1D-1 powers as it would be harder to replicate Earth's 200+ (although obviously a huge number would be minor).
My scheme didn't have '7' as a GOV type rerolled but in effect further subdivided that country so that lots of minor countries were possible.
I also note they bypass the whole 'apportion the pop between countries' by just making a referee decision about it.
Having had a play with this, I would either use WBH as is for balkanized worlds, or just design each one by hand for whatever effect I wanted to achieve. Unless someone can come up with something a lot more elegant than my poor effort!
tc