The Cottagers beat Everton in the Capital One Cup on Tuesday to end a six-match winless sequence at home, but are still chasing a second league win of the season following the opening-day defeat of Sunderland.
"The difference between being successful and not is nothing," said Jol, who was booed following Fulham's most recent home league game, the draw with West Brom.
"If we had won the game against West Brom, we would've been in the top half of the table."
Instead, Fulham enter this weekend's fixtures lying in the relegation zone.
Fulham are without first-choice goalkeeper Maarten Stekelenburg (shoulder), winger Ashkan Dejagah (calf) and defender Matthew Briggs (hernia), but defender Aaron Hughes (thigh) and midfielder Bryan Ruiz (ankle) could return if they pass fitness tests.
Jol has confidence the temporary move for Bent will pay dividends this term, with the England striker's start yielding two goals, despite being curtailed by injury.
The recruitment of Bent was better business, according to Jol, than Cardiff's big-money deal for Andreas Cornelius, who was signed on a reported B£8million deal from FC Copenhagen.
"We knew him (Cornelius)," Jol said. "He was on our shadow list, but I thought it was not only too much, but we couldn't afford to buy him.
"We've got Bent. That is probably not long-term, because he will go back to Aston Villa, probably.
"During the time he (Bent) is here, hopefully he will score goals and hopefully more than Cornelius."
Jol hopes Cardiff's open approach will aid his side, but he is also wary of the newly-promoted Welshmen.
"If you look at Cardiff, they're very organised," Jol said.
"They've got pace up front and they've always got some activity. They'd like to hurt you.
"It's not a walkover, of course not. It's a strong team with good qualities. They've invested a few bob as well.
"It won't be easy, but how many games are easy in the league?
"It's never easy. They will come at you, they will try to have a go.
"You get more space and normally it's easier. If you get more space with the players we've got - and we've got some space up front now - hopefully we can make it easier for ourselves.
"If not, I can live with a narrow win as well.
"Hopefully we are strong enough."