Jones and Islam had one top ten ranked win before fighting for the title (Bader and Hooker, respectively).
Khabib had three top ten ranked wins before fighting for the interim title (RDA, Johnson, and Barboza).
For reference, here are the other Lightweight and Light Heavyweight UFC champions' number of top ten ranked wins in their respective divisions before winning the title:
(5) Shogun
(5) Glover
(3) Chuck
(2) Rampage
(2) Machida
(1) Jones
(1) Rashad
(1) Tito
(1) Cormier
(1) Vitor
(1) Griffin
(1) Jan
(1) Jiri
(0) Couture
(0) Frank Shamrock
AVG: 1.7
Jones had a below average number of top ten ranked wins before fighting for the title (but he was also a replacement for an injured Rashad).
(5) Eddie
(3) Khabib
(3) Penn
(2) Benson
(2) Oliveira
(1) Pettis
(1) Islam
(1) Edgar
(1) Pulver
(0) RDA
(0) Sherk
(0) McGregor
AVG: 1.6
Khabib had an above average / Islam had a below average number of top ten ranked wins before fighting for the title.
In all fairness each had a unique situation.
Khabib missed weight in his 4th fight. That set him back.
-derailed his title chances
After he beat RDA he pulled out of fights with Cerrone twice and Tony then was gone for 2 full years. This is when he started to get a bad reputation for reliability “pulling out”.
-derailed his chances
Then he beat Horcher in a CW fight after 2 years away and was going to fight Eddie if Conor didn’t negotiate.
Fought Johnson and got a title fight
Then he nearly died making the scale for a title fight.
Then fought Barbosa.
Then became champ against unranked late replacement.
Then he basically only fought 1 time every 12-13 months and creates interim two title situations while having contenders knock each other off in 2/3 of his defenses.
This is why I like active fighting champions and hope Islam will be one.
Jon and Islam didn’t piss away many opportunities to the same degree, that’s why Khabib had those ranked fights.
So just to be clear. Jon in his 8th UFC fight was a title fight replacement.
Khabib missed weight in his 4th fight, pulled out of a bunch of fights, missed 2 full years only had 6 LW fights and 2 CW and had a title fight in his 9th fight but couldn’t make the scales.
All that said, if Khabib made weight he would have had 2 ranked wins and a title fight 9 fights in even with all that bullshit (weight missing, pulling out, being out a long time) he still had a title shot only 1 fight later than Jon.