The short answer to your question is that neither has been definitively proven. Some believe the single-source "shockwave" theory, others the multi-source harmonic theory. I am not aware of any hard evidence proving which is fact, though I continue to actively pursue it.
Personally, I am from the multi-source school of thought, because my belief is that the plasma wave from each A0 Blue star involved traveled in a direct line to the planet's L2 Lagrange point, where at least one now-shattered planet (T-IPZB I) was believed to have an isogen-5 cache. There are also many A0 Blue stars that did not experience an anomaly, and the "shockwave" theory would more likely postulate this reaction from most or all such stars.
If you have not already done so, I strongly recommend that you read The Seyllin Report
. In my opinion, it is the first thing anyone with an interest in these matters should understand.
You can find my full report in the Shattered Planets Datacore
Specific references to the 10-anomaly question are noted in the section entitled CONCORD's Fine Print