Yeah, I've struggled with that one a bit on a couple of attempts. Mainly, again, looking for super cow/gem starts as I shoot for HAs. Lack of forests though make it tough. Plus, worker steals are tough since warriors traverse a lot of flat land and often get killed by lions before getting a chance to harass the AIs. Getting nearby IMP AIs is a pain too as the spread like the plague.
I do have an interesting start that I've just played a few turns up to worker steal of closest AI. It's a double FP/corn start in the far SW with tons of other FPs, gold/luxes, copper and production. FP corn is ridiculous..ha. Bad thing is snail units. Great Plains can be wildly unbalanced...you just have to luck out on the right start