Polarity doesn't matter in our application, especially if using Three Delta...
If you wanted to get some basic visual line on the direction of a signal from just looking at the signals,
using 2 ferrites at 90°, then they should be in phase... otherwise, since we're TOA/TOGA, it makes no difference.
The 90° dual array, if loops phased the same, would present as below on a 'directivity' lobe,
but Blitzortung could care less, since it is not a DF system.
Can be handy for tracking a noise source, however, under proper conditions.