Let's see.
Gon vs Gido is on March 11th 1999. Gon' birthday is May 5. Since the Hunter Exam takes place annually in the 2nd week of January it is likely that
Chapter 1 took place December 1998 to January 1999. Three years from that exactly would be December 1995 to January 1996. Gon would be 8.
Kurapika's birthday is April 4th. He was 17 in the beginning of the manga. Kurapika fought Uvogin on September 2nd 1999. Kurapika was 18 when he fought
Uvogin. Four years from that exactly would be September 2nd 1995. Kurapika would be 14 when the Kurta clan was killed.
Now this is presuming that when they say three years ago and four years ago they mean exactly.
But September 1995 to January 1996 is a relatively close window. Just four months difference. If the "four years ago", "three years ago" is not exact it could be the same time. Not saying it is but at the very least when Gon met Kite, meanwhile it would have not been too long ago that Kurapika's clan was slaughtered.
---------- Post added at 02:20 AM ---------- Previous post was at 01:20 AM ----------
I'm probably wrong...but what if #4 was Gyro?
I'm not sure how old Gyro is now. Or how many years NGL is an official nation but I'll say Gyro is 31 and NGL is officially a year old in 2001.
Gyro would have started the NGL movement in 1991 at the age of 19 I think.
Kurta Clan Massacre was 1995. Gyro is 23 then.
What if...
Gyro was born in Meteor City. At 12 he kills his father.
At age 17, a tramp is falsely accused
At age 19, Gyro starts up the NGL movement
At age 20, Gyro orchestrates the suicide bombing of 31 people
At age 23, Gyro kills the Kurta Clan in 1995 and then secretly hires Silva to kill member #8. Soon after Gyro leaves the Phantom Troupe
At age 24, Gyro moves to NGL and becomes kingpin. Hisoka becomes his replacement.
At age 30, NGL is a full nation.
At age 31, Gyro becomes a Chimera Ant.
Now Gyro returns to Meteor City. I think he will fight the Phantom Troupe, defeat them and take over Meteor City.
Again, it's likely a huge stretch. But I have my suspicions of Gyro.
Plus I think #4 hired Silva to kill #8. This would explain the no infighting rule and the coin flip.