I think it's safe to assume that the majority of guilds with the best win/loss ratios are relatively low GP, but the majority of the best players in terms of "skill" (so not roster strenght) are in relatively high GP guilds. On top of that i think it's also safe to assume that relatively high GP guilds are generally better organized.
I'm not just saying that because i'm in a high GP guild, we don't have that great of a win/loss ratio compared to other guilds in our GP range.
That being said, i'm not sure whether or not the current leaderboard is an accurate representation of guilds their skill level. I'm sure some guilds would have been way higher on the ranking and other guilds way lower if we all had the same GP.
