According to Gonda, the Pannonian palatal shift did not become common until after the velar timbre shift (this was in the 3rd century, likely.) This suggests, in Pannonia at least, 5 preceded 3 by a couple centuries. So, perhaps both were independent innovations within the Danube provinces. I'm not quite sure about the changes in Romania, but if it was an independent shift, then 4. would fail to apply on account of 5. coming first.Aelfwine probably remembers the evidence on this chronology, if there is any, better than I do.
However, in Pannonian (and this is also true of Dalmatian), the velars still fell in line with the rest of the Empire.