Former champion Lewis Hamilton is joining the team from McLaren, as Mercedes ramps up its efforts to fight for the titles after a disappointing 2012 season.
Mercedes has also hired former Williams executive director Toto Wolff for a management role.
Ecclestone reckons Mercedes now has all the ingredients to be successful, and said he would be disappointed if that is not the case.
"I hope these [changes] will lead to Mercedes becoming much stronger," Ecclestone said.
"I believe Niki Lauda and Toto Wolff can do it. New people, new thinking.
"They will do the job. Mercedes have the best engine, top drivers, not less budget than other leading teams, so everything would be in place.
"I would be disappointed if they weren't there up front. There are no more excuses."
Ecclestone believes Hamilton's arrival to Mercedes will make the team stronger, and the F1 supremo has little doubt that the British driver will be a championship contender this year.
"I believe Mercedes to be much stronger this year because of Lewis. He will be a contender," he said.
"And if Mercedes are good, Nico (Rosberg) is there too. And you cannot exclude Jenson (Button) though I think McLaren won't be right at the front.
"I think it will be a very exciting season.
"If someone would have told me, say in 2010, how exciting 2012 would be, I [wouldn't have] believed it. I guess 2013 can even be better."