Probable The Last Airbender casting sheet?

According to a write-up by one of the protestors who went to the Flushing, NY casting call on March 1st, Paramount seems to be casting actors based on 'element nations'. Below is what the protestors found out on March 1st:

1) Water Tribe = Caucasian actors (evidenced by Nicola Peltz and Jackson Rathbone – Katara and Sokka)

2) Fire Nation = Indian actors (Dev Patel - Zuko)

3) Earth Kingdom = Asian actors (Jessica Andres - Suki)

4) Air Nomads = (possibly) Caucasian actors (Noah Ringer - Aang)

For a TV show with a setting that existed in an alternate universe (with borrowed elements from ours), the producers seem pretty bent on bridging the gap between our world and their's. Based on this info, this would mean that:

• Fire Nation = India
  

• Earth Kingdom = East Asian countries (China, Japan, Korea, etc.)

• Water Tribe & Air Nomads = North Americas (or maybe Europe)

How easy they make it for us to draw parallels and similarities based solely on race.