What defines how much exp/marks you get in Frontlines?

[Gor]

So how is the reward calculated besides who comes 1st, 2nd, and 3rd?

1st - 400XP, 600 Wolf Marks
2nd - 300XP, 450 Wolf Marks
3rd - 200XP, 300 Wolf Marks

You can get more Wolf Marks tho if your fc has the Mark Up I buff up that gives 5% increase or Mark UP II which gives 10% increase
If you're unfortunate enough to get on a losing streak for 3rd place in FL, you get a massive increase depending on how much you're failing; buddy of mine got 750 marks for being on a losing streak
You can also get increased xp from challenge logs