Can anyone come close to rivalling the front three at Barcelona. Messi, Suarez and Neymar. Surely the greatest attack in history.
They are all trying.
Real Madrid have Ronaldo, Bale and Benzema, which is close.
Dortmund have Reus, Aubamayang and Dembele.
Bayern have Muller, Robben and Lewandowski.
Chelsea have Hazard, Costa and Willian.
Manchester City have Aguero, Sterling and De Bruyne.
To reach these heights, Arsenal have to grab one more world class player, or risk losing Alexis who would probably make it into every front three in the world, except Barcelona's. Also, Ozil makes Arsenal's attacking unit a foursome. Liverpool operate more as a swarm so their front three are more a front five or six. High risk: lots of goals created and conceded. Manchester United and Tottenham look further behind.
Of the other richest (I think) twelve teams, I don't watch PSG or Juventus enough to have a worthwhile opinion.