Cyborg advance
If you've got a strong enough squad, perhaps including one or two snipers, you could consider taking the fight to the enemy. None of that sissy waiting-around defence nonsense; I'm talking about a full-on charge up the battlefield, and ain't no filthy covies gonna stand in our way! Well, perhaps a few covies might; but they'll wish they hadn't!
If your squad starts from sufficiently far up the field (initially held back by a suitably advanced blockade perhaps), you could potentially be charging into the enemy near their starting point, which should be quite a novelty. I need to explore the possibilities though; I think there's good potential but I haven't actually used this plan much yet. There may be some ways of engineering superior battling. Perhaps I'll expand this section later.
Difficulty levels
Unless you thin out the Elites in advance, on Heroic it may be too hard to make good headway without having to back off to recharge; so I suspect things would play better on Normal.