The right pec drill is an exercise to help you understand the feeling of late acceleration. You'd throw as many discs as you can without injuring yourself, as often as you can until you understand the feeling. Once you do, then you can throw with a reachback - still standing. Once you're doing that well, add a step. Once you're doing that well, and 2 steps. When that's done, do an x-step.
The purpose isn't to quickly get to an x-step, it's to try and maximize your potential at each stop. Thus, when you go from standing still to an x-step, you can actually see a difference in your distance without sacrificing all your accuracy.
An example would be, if you're throwing 250' now, inaccurately, after the drills, hopefully, you're throwing closer to 300'. That's because now you feel the late acceleration and keeping the disc in tight and good snap. So... right at 300' now from a standing position. Work at that and let's say you max out at about 315'. Pretty accurate. So you do an x-step and you're getting 325' now. Well, 10' isn't much to yap about. So you compare your standing throw and your x-step throw and discover that you're not doing the same things.
So you go back to the standing. Then the 1 step. Then the 2 step. This helps you build your base a little at a time. So you don't go from controlled 300' to a flailing madman with no idea where it's going for just another 25'. Once you come to the x-step this way, you should have more control and, I would hope, yield something more like 25'+ additional distance by adding an x-step.
I would also add that this isn't a month or two program. It's more like a year long program. You don't have to forsake all your previous throwing either. In the practice field, you do the exercises and drills. When you go play, you just let it hang out. Eventually, you should find that you're doing the practices and drills well enough that they can translate to the course (maybe a month or two) and then over time, you'll gain distance and accuracy.
Since most courses feature holes where throwing 300' accurately is all you need with distance, then it won't take long for a standing 300' shot to pay off. Then, for the holes and courses where you can really whale, you slowly develop the x-step so you can bomb with some idea of where it's going.