So, I've done a little research and you can bi amp the harbinger boxes no problem, but the rockvilles are a different story - mainly because they use piezo
elements in both the horns and the tweeters
this means that you can use the biamp inputs on the harbinger boxes, but would need to use the regular inputs on the rockvilles - still need 3 amps and a way to send the signal to both the crossover and the rockvilles amp
i.e. connect the outputs of the mixer to a splitter so that it can be sent to both the crossover and the rockville amp, connect the low out of the crossover to the low amp for the harbinger boxes and high out of the crossover to high amp for the harbinger boxes
because the rockvilles contain piezo drivers for the horn and tweeters, there is no benefit in trying to limit the freq range driving them - they naturally do not respond to frequencies below or above their active range - most attempts at putting a crossover into boxes like these is to limit
the effects of hf energy on the low drivers not
the effects of lf energy on the high drivers
we could still proceed with some form of biamp driving for the rockvilles if you want.
i would also caution you to consider that you may need at least one more amp simply to effectively drive the lf drivers in each box at optimal levels without compromising the impedance seen by any one amp