On paper, you can test out the balance and math of all the "action" more deliberately. So taking a "fast twitch" game and pretending it is turn based for testing. Of course, you can math out the win/lose percentages and hit rates and adjust your numbers. But one of the good adages in game design is to first make the math right, and then make it fun. Players will perceive different success rates than the math bears out. (See MtG and shuffling and land draws) You may have to adjust off the perfect math to create the experience you want your players to have. It doesn't matter if your game is "fair" if no players feel and believe that and stop playing as a consequence.