Spurs ran out 2-1 winners over Arsenal at White Hart Lane in the Premier League on Sunday to heap further misery on Gunners boss Arsene Wenger.
After failing to hang on to Fabregas and Nasri, who this summer joined Barcelona and Manchester City respectively, Wenger has seen his new-look team struggle to gel and they now appear in freefall after losing four of their opening seven games - one of which was an 8-2 drubbing at Manchester United.
Arsenal now sit just two points above the relegation zone and their pain was only worsened by coming away from White Hart Lane with nothing on Sunday despite controlling large parts of the encounter.
Tottenham, on the other hand, have now racked up four straight Premier League wins - thanks partly to the performance of Luka Modric, who they managed to hold on to despite strong interest from Chelsea.
It is a contrast that does not sit easily with some Arsenal fans, who are now questioning whether Wenger is the right man to lead their team forward after 15 years in charge.
Bale, who tormented the Gunners with his lung-busting runs on Sunday, thinks Arsenal have lost the reputation they once had that they were almost impossible to beat.
"Arsenal have lost a few players, which makes them more beatable I think as that has damaged the way they play," Bale told reporters after the win.
"We exposed that. I think keeping your best players is a massive thing. They are used to how you play and what you do. It is vitally important to do that and build your team around them.
"It is important that we have (Modric), and Arsenal were unlucky not to keep theirs."
Rafael van der Vaart scored his fourth goal in three north London derby appearances to open the scoring on Sunday and Kyle Walker sealed the victory with a 30-yard screamer following Aaron Ramsey's equaliser.
Despite admitting that Wenger's team have lost their aura somewhat, Bale thinks they will improve - but only over time.
He said: "They are still a great team. They haven't had the best of starts but I am sure they will improve.
"They have a lot of young players who are going to grow up in the next season or two and learn a lot. I am sure they will be fine."
Bale was a constant threat down the left for Tottenham on Sunday, but Scott Parker was arguably the best performer in Harry Redknapp's starting XI.
The midfielder put in a typically full-blooded tackling display to help neuter Arsenal's midfield and allow Modric to play a more advanced role.
Bale hailed the former West Ham man's contribution, and that of Emmanuel Adebayor, who excelled despite abusive chanting aimed his way by some of the Arsenal support.
"Scott covers every blade of grass and does a very important job for us," Bale said.
"Adebayor has been running the channels, holding the ball up, scoring and winning headers.
"For us it's massive to beat the bigger teams, and especially our local rivals, which is important - not just for us but the fans."
Walker's strike will live long in the memory of Spurs fans and in that of the 21-year-old himself given that it was his first goal for the club and it came in his first north London derby.
"It's a great feeling, my first north London derby and hopefully there will be many more derbies and goals to come," Walker told Tottenham's website.
"I got there first, took a touch and just thought 'if you don't buy a lottery ticket, you can't win', so just have a go and hit it.
"It was great to see it fly in."