Yeah haha imagine if real life sports teams were full of people not actually from the city or even the country they represent haha
They still managed to maintain a high win rate even before and after Genji was OP. Genji being OP just helped them a ton during the Summer Showdown. Calling them average at best is not true at all, they are definitely an above average team. Nobody expected Washington to make the playoff run in the way that they did though.
Cloud9 (owner of London Spitfire) initially wanted to build a western or mixed roster, including British and other EU players, but that entire plan was built around signing Sinatraa, so when NRG (owner of SF Shock) outbid them, they decided to pick up Korean players instead.