First question I have is whether or not your using a monitor or TV? The monitors can make a major difference in speed and ability to hit which is why most of the top players use a monitor or a tv with really good input lag times.
Second stop thinking so much about leg timing/hand timing etc. just like in real life the more you think the slower your response time is. That stuff is good to work on to create subconscious reactions, but if your thinking about it too much when the pitch is coming you’ve already lost.
Best advice max out your sliders for speed, go into practice, set it to legend and just react and hit. Don’t think just try and hit with that setup, then go into a game and the speed will seem a lot slower and manageable