We'd probably do it on US East, since that seemed to be where the majority of folks would show up.
As for Orcs, I hope you're being sarcastic.
Their long game can be pretty good in terms of sheer force, but early on leaves them a bit too underpowered to even defend from early attacks.
The Grunt is the most costly and one take the longest to build, in terms of entry-level melee units. And while this is supposedly balanced out by their higher attack, their defense is second best (at 1. The Human Footman has 2, and Ghouls/Archers have 0), one Orc against 2 or 3 of other units - not to mention the cheaper cost leaves more money for upgrades - is still going to get fucked.