The titles sequence of 'Marathon Man' were very 'normal' as title sequences go. The order was as follows:
Distributing company (Paramount)
Director (John Schlesinger)
So they did actually inform us of the producers and the directors twice which isn't that common. They put the big distributor along with its logo, to make it memorable, so you associate the whole film with it, and it also announces the start of the film. The most import members are usually seen to be first or last, so when it comes to making my own title sequence I will remember to do the same.
The actual film in this opening sequence did not give us many ideas of the plot or that it was a thriller, it was just a man running after a filming of a man running the marathon. The only clues that gave it away that it was thriller was that the music was slow and kind of creepy. Also you could hear the breathing quite loudly and the footsteps.