Learn English – “on and off” vs “off and on”

In your example

she and her brother

is the more natural choice since "she" is the focus of interest, "her brother" being a secondary reference. Consider the difference between

1) his friends, her brother, and she
2) she, her brother, and his friends

the references are reversed in #1 in terms of closeness to the focus, "she". #1 in understandable, but the listener must think more about the relationship than #2 which has a natural progression of relationship.

The exception is when referring in first person, "I" usually comes last. I was taught this was because of politeness considerations.

she, her brother, his friends, and I

This is more a question of good style than good grammar. When making lists of things, or comparing two things, it's good style to use the same sentence pattern for all the elements. For example, "Tomorrow we're planning to go boating, water skiing, and to scuba dive," is poor style. Better to say, "... boating, water skiing, and scuba diving."

Your example is a bit nit-picky, but the "to" is the problem word. As written the sentence is not as good as it could be, and should be "... subject either to total colonial rule or to varying degrees of economic control." Alternately it could be "... subject to either total colonial control or varying degrees of economic control."

So I agree that although neither sentence is actually "wrong", your sentence is better.