Was playing Javelin Sentinel after this most recent patch and wanted to play Siege Barrage and Divine Fury. I assumed that what would happen is the Javelins would hit the ground, and then explode out in Lightning Spears. I think it would be a fun interaction if this could happen, perhaps halving projectiles when you take Siege Barrage, if a further detriment is needed beyond the pretty crazy mana cost you would get up to taking both nodes.
Otherwise, I think it should be stated on either node, or both, that they don’t work together.