Ferrari struggled in the season-opening Grand Prix in Australia a fortnight ago.
Mercedes secured a one-two finish while Max Verstappen scooped the final podium place.
The Ferrari pair of Sebastian Vettel and Charles Leclerc came fourth and fifth, respectively, which was way below their expectations.
Worries have been raised over whether the Italian outfit are failing because they have adopted a different front-wing philosophy to their rivals.
But Marko does not believe that is the issue.
“I think that [theory] is overrated,” Marko told Autosport.com.
“The front wing more or less determines the concept of the car.
“But there are many other things in the front area that play a role as well.
“There are the different concepts, but in terms of race pace only [race winner Valtteri] Bottas was a step above the rest.
“Ferrari and [Red Bull] were on the same level.”
Instead, Marko believes the F1 authorities have tightened some regulations which Ferrari were exploiting.
“The FIA reacted very well and closed several loopholes, or at least minimised them,” he added.
“This means that these speed peaks, which Ferrari had on the last 25 per cent or 30 per cent of the straights, no longer exist.
“That’s good.”
Red Bull will be looking to continue their strong start to the campaign at the Bahrain Grand Prix this weekend.