Wendy used separation technique on Touka who one shot Gajeel. Lucy also 100% used transformation on Erza level characters as she literally used it on Erza to turn her into a fish.
Touka was powerless when Wendy used her enchantment and this has nothing to do with actual combat abilities. Touka has never defeated Gajeel in a hand to hand combat. We have seen her fighting capabilities, she was taken down when Happy threw an orb at her. And Lucy used that on Erza who allowed her to. I haven't seen her doing that on actual opponents ready to fight, and all of her opponents in the sequel are weaker than Erza.
Also nothing you said changes anything. Urano Metria did more damage to Jackal than a full powered LFD attack, so saying Gajeel was able to tank an LFD attack means nothing especially when he was practically defeated by it.
I would like to remind you that Natsu defeated Jackal in his etherious form (which would be significantly stronger than his base) while Lucy took down Jackal in his base form. While Urano might've been at nest comparable to a LFD punch in Tartaros, Natsu has grown much stronger since then and trains way harder than Lucy.
Also nothing suggest Gajeel is on Kyria or Nebal level. Even Madmole tanked a FDK attack which is superior to LFD attacks and Kyria and Nebal are on Madmoles level.
Kyria doesn't scale to Madmole in durability. Neither does Nebal. Madmole is a dragon slayer that specializes in defense. The other two do not.
Kyria was on the verge of defeat after taking Erza's flame empress which a small fry compared to what Natsu can dish out with FDK. And Nebal was struggling with base Wendy lol before he went dragon force.
Gajeel has no feats to suggest he could defeat Wendy and Lucy together and barely have feats to suggest he can do it with them individually. Even Taurus form Lucy did more damage to a golem than Gajeel iron did so nothing suggest Gajeel stronger than Lucy.
He does lol. The fact that he can push LFD Natsu to exhaustion while Athena 2 (stronger than Wendy) is getting overwhelmed and Nure-Onna Lucy (far stronger than regular Lucy) was stated to be oneshot material says it all.
Disingenuous to compare her with base Gajeel, who took down a golem right after while Lucy needed to use a Star Dress Mix. Gajeel was more exhausted than Lucy and fought a stronger opponent. Natsu > Strauss siblings.
Also Aquarius saying what she said means nothing as we already saw Lucy withstand stronger powers on three separate occasions. She was able to take a hit from Dragon Merc, withstand Natsu heat while empowered by Ignia and she was able to withstand the heat from Ignia himself. She also tanked a full on attack from Alta face.
Everyone took hits from Dragon Merc. Gajeel survived Aldoron and Acnologia's attacks. Natsu's heat is nowhere close to what a full powered Ignia can do. Happy and Carla tanked Ignia's heat lol. Everybody in the labyrinth did.