Top Premier League clubs may have splashed the cash but the results are not backing their investments this season.

Last weekend - when only Arsenal claimed all three points - brought some inherent weaknesses in these teams to the surface.

Manchester City, who spent more than £150 million (S$317 million) in the last transfer window, appeared toothless without three of their most influential players - Sergio Aguero, Yaya Toure and Vincent Kompany - as they slumped to a 2-0 defeat by Stoke City.

By all accounts City, equipped with the best talents to win the league, need their fit players to stand up and be counted while the injured trio recover.

However, recent 4-1 thrashings by Tottenham and Liverpool have raised deep concerns among City fans, and the club need a consistent run soon to get back on the title hunt.

Their city rivals, Manchester United, have no such defensive worries. In fact, they are the league's best defensive team, with only 10 goals conceded.

Their desperate problem is scoring. And fans are putting all the blame on manager Louis van Gaal's dour tactics.

United do keep it very tight at the back. It is not necessarily a bad strategy but scoring will be a big problem if there are no crafty playmakers or incisive scorers.

Sadly, that seems to be the case for United, who have scored the fewest goals (20) among the top six teams. Their last match against West Ham ended in a 0-0 stalemate.

The new players whom van Gaal brought to Old Trafford are letting him down.

Anthony Martial and Memphis Depay had started brightly but have seen their goals dry up.

Yet, as much as the two Manchester clubs are in trouble, it is Chelsea - the original billionaire club - who are suffering most, languishing 14th in the league.

Losing against Bournemouth at Stamford Bridge? The defending champions only two points from relegation? Who will put his money on that?

Jose Mourinho has run out of excuses and ideas, his team's confidence is at an all-time low and he is lowering expectations with every match played.

But, as the top clubs continue to drop points, it opens the door for unheralded teams to challenge for the title.

Current leaders Leicester City have been the complete opposite of Chelsea - incisive, well-drilled and united.

I believe that they are serious contenders to break the dominance of the top clubs and finish in the top four. In fact, they even might have a long shot at the Premier League title.

And, with Liverpool getting revitalised under Juergen Klopp and Arsenal alternating between unstoppable and brittle, this is shaping up to be the most unpredictable season by far.

Leicester, not among the big-budget clubs, are at the top.

This proves that football is a sport, not simply a money-spinning business.

Finally, we can see that money does not buy success.