I'm not saying those results wouldn't change.
What I'm saying is that if you turn 3 losses in to draws through having better defenders you get 3 points. If you turn 3 draws in to wins by getting better attacking players you get 6 points.
Most teams that win leagues don't have to defend much because they normally have the best midfielders and attackers so they control posession, create more chances and don't get attacked often.
People assume that the teams that have the best defensive record must have the best defenders. That's often true but it's often the midfield shielding the defence from attacks and not giving away posession that makes the defensive record so good. If you don't lose the ball cheaply, you minimize the ability of the other team to attack you.
We struggle to beat the top 6 teams because we rarely look like scoring against them because our attacking players aren't on the same level as a unit.
If we want to beat the top 6 teams we have to beat them, not draw with them. We can spend as much money as we want on great defenders but it won't help us as much as it will if we increase our attacking threat and ability to score goals.