I have experience with this from the other side as I was in a league 1 competitive clan whilst playing Quake Wars for the PC. Our team was made up of four people, and we for the most part tried to play on promod with other competitive players of a similar or better skill level, unfortunately you can't always organize a scrim/clan war, so sometimes we'd go on pub against unorganized players, and for want of a better word we'd rip through them, and quite often be accused of cheating by other players, players might I add who had only played for 10-20 hours, when each of us had racked up over 2000 hours ourselves, with a 1000 hours at least working together.
We were all incredibly close having suffered heavy losses before and brought back nail biting games at the last minute, so our level of teamwork and coordination along with our friendship was great, allowing us to play extremely well together; we worked extremely hard and devoted hours upon hours every day to be THE BEST. That means hours going over tactics and strats, hours tweaking configs to improve performance. Simply put if you want to be the best then you have to work for it, so don't accuse competitive level players of cheating, they just want it more than you, otherwise you'd be at their level too.