I am not sure that's a strong enough argument against Eto'o. He has won 3 Champions League finals (scoring extremely decisive goals in the first 2). And has won 3 finals with his nation. Of course he's also scored and won domestic finals for Inter and Mallorca while Drogba has lost all his international finals but the 2012 one even though he was impressive taking Marseille to the UEFA 2004 final and Chlesea to the CL 2008 final.
This being said, the 3 are very close. Salah, if he wins something with Egypt might end up even higher given that his club career can still get more impressive than the other 2.