The relationship shown between Clark and Oliver mirrors the one Superman and Batman share in the DC comics. Even the love story between Lois and Oliver mirrors the one Lois and Bruce Wayne have before she falls in love with Clark.
Green Arrow's method of stealing the rich and corrupt, helping poor people is a similar trait of Robin Hood's. Hence there was a reference to Green Arrow as the 'Prince of Thieves' which is also how Robin Hood was known in English literature.
Green Arrow is an archer in DC Comics who invents trick arrows with various special functions, such as glue arrows, diversions (smoke), net, explosive, time bomb, grappling, fire extinguishing, flash and tear gas arrows, as well as cryonic arrows, and even a kryptonite arrow. Here only smoke arrows were shown.