“I like some aspects of one array and different aspects of another. Can I combine two different main arrays?”
Don’t mix main arrays
In general, when using classical techniques (main array with spots), don’t combine main arrays – this causes comb filtering/phase issues because of the difference in time of arrivals to the two arrays.
If you want to combine, say, the warmth and spaciousness of an omni-based spaced AB array with the crispness of a cardioid-based XY, you need to consider these a 4 mic array and place the mics with that in mind.
(In the case of the 4 mic array, the cardioids in the XY would be at a similar distance or even closer than the AB, rather than 1.7 times farther away, as distance factor might indicate.)