Think he has potential to become better than Lenglet and I think he could do it very quickly if it came to that.
His performances against Celta and Huesca were kinda ridiculously good for his age and the extremely limited playing time he's had for us. His passing looked crisp and he was extremely confident in splitting players and playing through pressure.
Honestly, I would love to experiment with him at CDM. I think a midfield of Frenkie-Todibo-Arthur could be great in the not too distant future. I think Frenkie and Arthur will naturally develop into better chance creators. They have been visibly improving in this regard over the course of the season and will no doubt get better training/playing next to each other.
Todibo is quick, athletic, tall, and shows poise with the ball at his feet. His eagerness to ding passes through lines could really allow our other players to do their work way more effectively. Barca are only a midfield reinvention away from being a much superior team than any of Europe's giants.