Well I personally own and play two accounts (byzantinist and byzantinekitty) which are both gold level accounts (in that their cards are gold level) which is why they are in gold league.
I also own two silver level accounts where I let other, newer players play them and we split the winnings.
And I play two accounts in ranked (both Champion league) owned by other players and we split the winnings.
To be at the top of the gold leaderboard requires a combination of skill, good cards, and time.
Rumor has it he is also kick-ass
As I said: "And I play two accounts in ranked (both Champion league) owned by other players and we split the winnings."