I would definitely configure the V3 so that the rolloff has a -6db/octave slope not -12db/octave (not sure how it is shipped stock). Personally, I've also configured mine so that the rolloff 1 is 100hz and rolloff 2 is 50hz. This seems to give me two useful rolloff settings. Though I am debating switching it back so it is 75hz and 125hz -- probably would never use 125hz rolloff, but 75hz might be a better all-around option than either 50hz or 100hz.
Once you configure your V3, if you use any rolloff, I would use the V3 not the mics. I don't know about the MGs, but most mics have a rolloff slope of -12db/octave or -18db/octave which is pretty severe for the type of recording we do.
That said, I wouldn't run any rolloff for Mule. It might make sense in the future, but for now you should learn what your equipment can and does do when unleashed. Then you can make informed choices later on whether to rein it in.
Of course, what do I know? Last year at Mule, Markham and I were both faced with a similar choice, since I was running my AKGs for the first time and he was running his U89>m148.modSBM1 for the first time. Both of us ran with no hpf, and both wound up with too much low end.
There's always post-processing though.