The oldest brother on the left is Duster: Duster, affectionately called Sloth, is the fastest of all when it comes to racing. He’s arrogant like his mother and could use a mouthful of somepony else’s dust sometimes. He’s working towards starting up his own racing group like the Wonderbolts, though he’s unemployed and has no income.
The youngest one on the right is Dazzle Coin: The pegasus dubbed Scrub is a successful buisnesspony in the Crystal Empire. He’s the kind of pony who could say that the sky is red on a perfectly blue-sky day and you’d say ‘oh, it IS!’, which makes him perfectly good for selling contracts or anything like that. He’s honest, though, and very smart, so he won’t sell ponies cheap, dirty products. He has a fascination with unicorns, and wishes he was born as one instead of a pegasus. He’s satisfied where he is, with the exception of his wealth always brings his brother begging for bits.