Again you are falling into the trap where if you extrapolate the numbers down to 100 guilds kill the 1st boss and 99 guilds kill the last boss as we have trivial content. go further and by doing the same flawed math you can have a brand new single instance and lets say 1 guild in the world gets there and they finish it. by this flawed math we are having an instance that is either the easiest in the history of wow with 100% clearing ratio or the hardest one since 0% cleared it if they didnt finish it.

Of course it is easy to see how flawed math is flawed when you put it to the extreme but the same exact flaw is in your numbers and how you judge them right now it just isnt as obvious for the untrained eye as they say.