Oda just doesn’t care about these things. IJ should be stronger than g3 and roughly comparable to g4. It becomes tricky with acoc involved, g2/g3 with acoc can be stronger.
Pre ts :
G2/g3 was > ashura /santoryo zoro >= DJ Sanji
Since luffy defeated someone twice stronger than kaku and jabra
Luffy also went on fighting stronger people afterwards again.
Post ts :
G4 > Zoro ~ G2/G3 >= DJ Sanji
Wano :
Ryuo G4 > enma Zoro >~ RS Sanji ~ ryuo G2/g3
Since onigashma PUs :
Adhaki G5 > Adhaki G4 >= G5 > adhaki G2/G3 >= KOH Zoro >~ IJ Sanji ~ G4 > Zoro (no CoC) >= G2/G3
Until Zoro and Sanji can fight a top tier like adhaki g2/g3 did against drunk Kaido, they are below for now.