Messy Macedonian civil war over the succession. Not sure who the other possible Argeads are, off hand, but lots of ways this could go badly - and scuttle any plans for Persia for a while.
The next king would be Amyntas IV, who had been deposed in his infancy by Philip II, his uncle. IOTL, Alexander had him killed after having become king.
The next king would be Amyntas IV, who had been deposed in his infancy by Philip II, his uncle. IOTL, Alexander had him killed after having become king.