Why would DC be above him?
DC only has 7 LHw wins, to alex 6. Alex is 5-0 in LHW title fights. DC is 4-2
One more LHW win and they are tied on wins with alex having more defenses and no losses.
Barely surface level analysis. Its great to copy and paste numbers, but no one in the division is in the same stratosphere of the Jon Jones that beat DC twice.
For the record, Alex is a phenomenon, an exciting fighter who is willing to step in anytime (no doubt a product of his Kickboxing career ), and someone with game changing power paired with technical ability. A very scary combo.
However, he is fighting in a wasteland of a division left after Jon Jones held dominion for basically a decade. He is fighting in a division where old man Glover, as much as I love him, was able to win the belt while a younger version of himself couldn't win it and was only able to get to one title shot.
This is why the talking point of "he beat X number of former champions" is more marketing than not. Still an impressive feat, but not all champions are created equal. His best win in the UFC to date is Izzy when he was a Champion. Izzy had 6 title wins, 5 being defenses at MW. You can beat 5 guys who played hot potato with the belt and it would not count as much as beating a guy who held the belt for 5 defenses.
The quality of the division and opponents is constantly discussed when comparing fighters in different eras. There is a lot of recency bias with Alex, and I get it, he is exciting, but in the division he has only 4 wins, 2 against the same opponent. All primarily strikers, his overwhelming strength.
Is it his fault that there are no opponents of the quality of LHW during Jon's reign? No, but that is still a factor to consider when trying to rank him.
Can he pass DC and the rest of the elite LHWs during Jon's day? Yes, he needs to keep beating new comers of all styles, rack up those defenses.
My opinion? He should go for achievements that have never been done. Go try to grab a third belt. No one is going to be LHW GOAT or MW GOAT anytime soon, HW can still be done. Get the third belt, defend at HW to break the record, and he will be in a league of his own.