Actually, wasn't the change just that WPs get destroyed first always, and all other cargo gets destroyed in the old method? Still has the same effect though, as ships stop shooting at the planet when WPs are gone (assuming troops are available ).
In fact they will stop shooting at the planet as soon as all armed WPs are destroyed. I've captured many planets with intact weapon platform but with no weapons at all or just PDC. In addition, I've captured planets with sats and mines still in cargo.
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