[...]
As a matter of fact, I'm currently testing the team since I had these 3 Pokémon ready in my boxes and only needed to retrain them. As I write this, I'm at battle 83 and have been very impressed, I was skeptical, but it's been working better than I thought. M-Blaziken is probably underrated as a hyper-offensive option for singles, and Ferrothorn has been an absolute monster, the glue and true MVP of the team so far! I was skeptical of the 2 inaccurate moves, but misses are very rarely a big deal. Latios, on the other hand, has been handy for its resists, but feels like the weak link, both offensively and defensively. With no bulk investment, it can't repeatedly tank resisted hits, and usually finds no time to Roost, while the Z-move barely misses out on many KOs.
I have also noticed some of the criticism come into action: Ferro is indeed the go-to switch in for water-types and inevitably receives a lot of Ice Beams and Blizzards, so I can see a loss to freeze coming at some point in the future. Also, the "no backup plan" point mentioned rings very true, as sacrificing Blaziken or Latios is sometimes a necessity without knowing the last Pokémon and whether you will need them or not. But the typing synergy has been making up for it thus far, since it's often possible to find a good switch-in and preserve.
My (preliminary) opinion from these battles would be that the team would need quite a large amount of luck to reach 400, especially if movesets aren't being looked up. But there's no denying the team is pretty good (and fun!).
If anyone else is interested in a similar exercise, I made a QR code, the EVs are exactly as instructed by Touko:
https://3ds.pokemon-gl.com/rentalteam/usum/BT-4AE1-8D7E
I'll report back once my streak with this team ends with any additional thoughts I will have gathered about it!