To give it a proper go you need quality players in every position!, this will mean upgrading if neccessary, the main thing is pick a formation and stick to it!, there will be ups and downs as this is how this game works!, the more you change formation the harder you will find consistency!, strengthen every position to about equal quality for the formation you choose then get a player in the same position for every position as cover1, so in effect you have two teams!, your second string doesnt have to be as strong its main responsibility is for cover, you can slowly upgrade that aswell over time!.