Well, 'Hidalgo' has roots in true events, but it's not a strict, 100% accurate retelling. Some aspects have been fictionalized or enhanced to create a compelling film.
It's hard to say for sure. Some parts of the Hidalgo story might be based on real events or people, but it's likely that there's also a fair amount of fictionalization and embellishment.
They could interact through a series of codes and puzzles. For example, Carmen Sandiego leaves a trail of encrypted messages that only Le Shiv and El Topo, with their own set of skills, can decipher. This would lead them on a chase to find Carmen and join her in her next adventure.
Maybe there could be a plot where Le Shiv and El Topo are having relationship problems. Carmen Sandiego, being the wily and intelligent character she is, helps them work through their issues while also enlisting their help for one of her heists. This could show a more human side to Carmen and also explore the dynamics of the relationship between Le Shiv and El Topo.
Since we don't have much information about the 'Expulsion Carmen Secret Story', Carmen could be anyone. She might be a student if the expulsion is from a school, or a member if it's from an organization.