I don't have the game yet but this looks like an absolute nightmare if you want to stay on level curve. The level gaps are constantly shifting between one half of the map and the other and don't look like they feed into one another at all.
For what matters, I've managed to stay on curve following that "guide" until the lvl 40 bits.
I ended up doing the flying titan first "on accident" cause i ran into it without even thinking which is funny, and I also did Mela first thinking she'd be the "first" one without knowing that the dark guy was actually lower level.
However after you reach level 40ish even if you're just using 6 it starts to get difficult to be on curve without actually grinding a bit. I've been fighting every trainer I found, and rought estimate means I've beaten around 70-80% of them, and interestingly rn I've cleared all the gym-camp-titans (but not the final bit of each story) and I actually am significantly underleveled! My highest poke is lvl 51, and i got demolished by one of the various first fights of the final bits which has lvl 60ish teams.
Guess it's time to sort the pokedex and meanwhile pick up some candies from raids to catch up.
Idk what to think of it, it's not a complete faceroll but mainly due to the level curve being questionable in the final bit.