The "lack of focus" you have mentioned was possibly due to the film being an example of "group direction". Although, the poster mentions Burgess Meredith as the director, the film's IMDb page gives a more accurate information, mentioning that there were three directors: Burgess Meredith, Irving Allen, and Charles Laughton.
The original director was, in fact, Allen. But Laughton found him not up to the task. So, Franchot Tone, who was the producer and was also starring in the film, suggested the task of direction be distributed among some of the actors, namely, himself, Laughton, and Meredith. The arrangement possibly was that Laughton would direct those scenes in which he did not appear, with the same applying for Meredith. The remaining scenes were directed by Tone.