Well, you had Timoleon a little before Alexander's reign, and then you've got Agathocles gaining a lot of power shortly after Alexander's death. You've also got Alexander of Epirus, Alex's uncle, fighting some in Italy during Alexander's reign, and he had success, but would eventually be killed in battle. You could probably do something with both him and Agathocles, seeming how the Epirot is in Italy and Agathocles in Syracuse.
Not sure about Massalia... they probably just traded and warred a bit with the neighboring Gauls. Nothing too exciting.
Besides that, Wikipedia's your friend. Look around on there, and you'll likely come across something in the appropriate era that you can use for your timeline.