Here's a different way of looking at it. There's a spectrum. On one extreme are the full liberals. On the other are the authoritarians. Everyone else ranges in between.
The full liberal attitude is this: if something is thought by a liberal to meet with God's disapproval, like watching T.V., then the full liberal takes the attitude "I won't watch T.V., but I won't stop anyone else from doing so, because (from the Koran)
there is no coercion in religion. This can be further explained by the reasoned point that you are only doing good in the eyes of God if you do so voluntarily. Not watching T.V. because you want to but the Taliban have banned it gets you no points in the eyes of God.
The full authoritarian attitude is that God wants you to make the whole of society bend to his will. So, if the authoritarian thinks T.V. watching is wrong in the eyes of God, he wants T.V. banned under the law of the land. He wants a theocracy.
If we look at all the groups described as "radical" in the O.P., they are all strong supporters of theocracy: full on coercion.
The reason that the author of the O.P. article might have perceived leaders as being of great importance could be because authoritarians tend to focus around strong and obvious leaders, and liberals are more naturally individualistic, and their leaders will be theological guides and (by definition) would not be authority figures. But both groups can have leaders who have influence over theological interpretations, like whether or not T.V. is bad.
To complicate matters, there are many different theological interpretations at any point on the spectrum. T.V. might be fine for some liberal groups and not for others, and it might be legal in some theocracies but not others.
Liberal doesn't mean lax observance. The liberal might be very strict with herself, just not with others. The extreme liberals, it goes without saying, are innately tolerant of other beliefs. The authoritarians can tolerate other religions, particularly Christianity and Judaism, the people of the book, but these have lower status. If they are extreme, and you are a pagan, polytheist, animist or atheist, flee as quickly as possible, or keep your mouth shut and pretend to be Muslim!
People here are more familiar with Christianity, and of course there is a similar spectrum. The difference is that there are relatively few sects left that are on the far authoritarian side. There used to be far more, and their enforcement used to be far more vicious in the good old days when heretics were hung.
Does that help?
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