Latency on in/out through outboard v. no outboard?

[Animal]

PT LE (5.x and 6.2.3, depending), 001, G4 800.

I like to send my drum submix through a compressor and tuck it underneath the uncompressed mix. Of course, when I do this in PT, I have to set up the same compressor on my straight submix as on the "compressed submix" and just bypass it on the "non-compressed mix" to avoid latency issues. But I'd like to save some DSP and just send the submix to an outboard compressor. So if I have the drums submix on a stereo track and just send out it 3 and 4, and bring it back on 3 and 4, will that give me the same amount of latency as if I send it out 5 and 6, through a compressor, and back on 5 and 6? If so, I would just run one submix out and in, and one out, through a comp, and back. Am I making sense?