So far from my experience in 1.8, rebel stacks are always around 90% of your FL. Now this works fine with me, even though it is slightly unrealistic. Now the problems comes in when you have a a large empire in Asia (as a European), with provinces scattered all around the place. What a normal player would do and what historically happened was that there would be an army in Europe and then a few separate armies around the globe. The problem is that whenever there is a revolt, the only way to crush it is to move your whole army to one place, because the individual armies are not large enough. This does not make sense at all. I mean why would let's say England have to move all their troops from India to England (travel time of about a year), just to put down a revolt of reformed zealots. The separate armies are meant to deal with revolts in one specific place. You can't increase your FL, because that just increases the sizes of rebel stacks. The only way to solve this is to go over your FL. Revolts should not be scaled not FL. Revolt sizes in 1.7 were so much better.