That isn't a dumb question at all.
I'm guessing that you are deciding whether your 12v system will be built around the smaller Danfoss DB35
compressor or the larger DB50
compressor. Am I on the mark?
We had exactly this problem and we chose to install the larger compressor on our system, because what we had was at the top end of the smaller compressors recommended
cooling volume.
I'm no certainly expert and so I may be completely wrong, but my (limited) understanding is that the more powerful system will run for less time, but not 1/3 of the time. Will it be more efficient? Hmm, depends how you define efficiency.