If you think about it. The signal would do through the first speakers crossover and then into the second ones. The second speaker would be getting a weird fractured signal at best. Parallel will be the tougher load but the signal would be correct to both speakers.
The dampening is going to be fairly low at 3 ohms or less. If it’s not direct coupled there is very little dampening anyways (caps, inductors, or resistors) in the way. Even with a 6db first order the dampening is very low at less than 3 ohms.
Some JBLs use to wire their woofers out of phase too.
Parallel get’s my vote too. You’ll have good sound effect if you don’t have anything else. Stereo with 2 full range speakers playing the same frequencies per side or in 4 corners or ????? Just so you know it seldom works. There is a problem with the mids and highs being way to far apart in two enclosures. It’s impossible to get any cohesion between two sets of mids/highs in separate enclosures, the acoustic centers would be WAY off to say the least.
The better solution would be to disconnect at least the highs on one pair of speakers. Maybe the mids too, it just depends how far from each other the mids are vs how close together you can get them.
Remember Bose drivers pointing in every direction. Sound effects at best, not a lot to do with stereo reproduction at all..
Regards