Never could find a set path/walkthrough online I considered "best" for me, so I set my own path based on how it felt.
1. Clear the area near Rastigan, and then his path to the Tower of Courage. Don't take that quest until you're standing outside the door.
2. Take the "wailing lord" quest from him once the tower is clear, and clear your way to the battle field.
3. Clear the area near the tents on the battlefield to spawn 2 quest givers, taking both.
4. Complete Army of Darkness (dragon liches and Priest of Menzies in center of battlefield.)
5. Proceed to and clear Temple of War, taking the Forgemaster's quests (all of them). Also grab Lord Taeres quest on the way out.
6. Go out the back of the temple to Nimros the hunter (straight ahead instead of going through spider cave). Take the shard wolf quest and kill the first one now behind you.
7 clear out the spider cave, then go a bit further on the beach to take out that shard wolf. Go back the way you came to clear the last spider spawns (they drop shards).
8. Head straight out of the spider cave entrance, then head to your right to Khobay the Betrayer.
9. Heading back, go again to your right up the hill and clear everything around the Tower of Courage (another shard wolf here). At this point, you can either run back to the temple to spawn and wait and escort the Tower Mage to the tower of courage, or do this later.
10. Go down the hill in front of you toward the gaggle of patrolling hydras and storm riders. Take the quest from Miko the Unchained, and plow ahead through the burning forest. This will probably be your spot where you might die, so don't over-aggro.
11. Keeping in the same theme as before, head to the right (after turning in your quest) and head back to the battlefield. Take out the shard wolf on the way across toward the wailing lord forest.
12. Clear the forest on the left side, then start pulling the banshees across. You want to flag heroes so they/and minions don't gank the wailing lord.
13. Clear new spawns around the wailing lord, but don't. Take his quest just yet. Take a left back across his bridge and a little bways forward, take out the shard wolf.
14. (Optional) flag heroes to the first clearing in the forest straight ahead from the wailing lord bridge.
15. Take the griffin quest, go right, and pick up the griffins. Hurry forward and take out the spawns on the way out of the forest. Escort them to the right back toward the first tower where Rastigan is. If one of them takes considerable damage during a fight. ?et them regen before going on.
16. Take out the last shard wolf, then head toward the temple. If you skipped finishing tower of courage earlier, go do that.
With everything cleared, go turn in any quests for rewards you still have left. Total quest xp is 100k, so kills xp is just bonus at that point.