Irrc there's no mention of m3 afyer ts, but yes oda potrayed three of them at FI..
You just prove one of my point, even before TS oda choose to group lufy and zoro together more than sanji with both of them being WG..
And iirc Nami is the first to create the definition of M3, it's because their inhuman prowess they posses within the crew, and we know Robin didn't have the strength to lift building like those 3, and then franky joined and yet Franky is not as capable fighters as those 3.. and then come after TS they're all became stronger in their own right.. then come wano jinbei join now the crew had one addition of monster, so the crew had 4 monster,
what those 4 monster have in common isn't strength but that they belong to the monster within their crew..
Oda put Luffy and Zoro within Striking distance while stronger than both Sanji and Jinbei but still oda seemingly put sanji stronger than jinbei
but then again oda also went ahead to portray zoro and sanji together in Little Garden zoro and sanji are symbolized to be Dorry and Borgy (its obvious since they fought over the exact same things)
And whenever luffy and zoro have a moment sanji would be gone doing something else or is asleep lol. like in the sea train stretch.. while zoro and luffy were on the train sanji was whopping asses in the sea train as was the first one at that moment to come close enough to break Blueno's tekkai.in enies lobby the enemy luffy faces is twice as strong compared to kaku and Jabra.. who sanji and zoro were fighting
And while luffy fights lucci zoro and sanji supervising ussops shots to save robin..before sanji diverges and opens the gate of justice to save the crew
Fast forward thriller bark... sanji and zoro shown to be neck and neck with eachother...working as the central core for the straw hats attack combinations..
Fast forward Sabaody and we see luffy /sanji/ zoro having their attack combination
still maintaining their hierarchy
And the reason behind why isn't sanji in WG should be obvious.....
zoro got his bounty from wiskey peaks
while sanji was the MVP of both Little Garden and Alabasta... yet he didn't get his bounty..
his first bounty was after enies lobby and that was off 77 mil... if World G knew what role he played in SHPs success he would have gotten a bounty post alabasta which wouldn't be less than a 30mil...then his bounty would have exceeded 100 mil making him a part WG
so the obvious reason being him being under the radar... that quality about sanji makes him so unnoticed...
The thing with post time skip is that.. things aren't that linear.. they are hectic... like zoro and sanji haven't had a well deserved fight since pretime skip to show their ceiling.. but from what is shown even in Post timeskip they still seem relative.
So that the reason why oda doesn't have sanji in WG.. nit because he is not to their level its because. he's better under the radar
and why oda has zoro with luffy is coz he is the Vice CAP... just like killer in WG..
so oda shows characters acting claiming that why isn't he the captain coz of his strength... but he also shown that his everyday chef rivals him at that..