It'd be very easy to test, but you'd need three people to do it reliably and I haven't found two others with interest in it.

So many threads about this already.

HP stacking trumps all for the following reasons:

1. Priests and grunts heal a %.
2. Flags multiply your total hp IIRC, not your base.
3. Armor items do not justify their cost.
4. Special attacks ignore armor.

Are there exceptions, yes, but those are so rare as to not be relevant.  First, no one plays QOT, and if they do, they'll be dead most of the time anyway.  LE can reduce your armor, but you just hit him with a stun immediately afterwards and the armor reduction wears off before he can take advantage of it.  And anyway, you'll end up with some armor as a side effect of getting your HP items.  About the only time I will take armor, not stack it mind you, but get at least one armor heavy item is when the other team has a tower rook or mass minions.

I played a game the other night where a Sedna managed to get 9K hits.  If she had spent all her money on armor, she'd be dead in 3 special attacks because they ignore armor.  As it was, she was basically unkillable between her minions, priests, self regen rate, and casted heals.

I don't know of any generic strategies that invole getting Groeffling warplate by level 10. There is too much other stuff to buy at that point in the game.

Obsenitor, I'd be interested in trying it out as soon as I can find my CD key. I have to find it.

(Btw, QoT + Mana Cape + Leviathan = hella good)