Couple little issues with the Azusa=Wanderer theory (fixable with some storytelling, admittedly):
1) She is human and therefore mortal. She could have sparked pre-mending, but she would have lost the planeswalker-associated immortality during the mending about 60 years ago.
2) The Wanderer is a white-centered character while Azusa is green-centered.
for 2. Simplicity is they already filled ajani and hualti for the selesyna slots Tamiyo is bant and she was only simic in war
No, it was the fact they didn't have enough mono-white planeswalkers so they made Teyo and pulled Wanderer a from future storyline to use a sneak peak (same for Kasmina and Dav for blue and black). They consider Ajani for mono-white but GW has even less walkers so they left them there.
What did you hear Charlie Brown noise that adults come from me
that’s not what I’m talking about
is there even one color combo in 2 color that goes above 2 walkers…no
by The way kasmina is a bad example for your arguement her real colors is simic not mono blue