The Futsal training sessions that I saw in Spain were completely different that what we do in the US.
The warmup starts with having the player run 6-10 laps around the Futsal pitch and then the loosening is all static. After the warmup/loosening the head coch will start showing drills on a white board and then they will all move to the pitch and do the drill on the pitch.
There are times that the palyers wont even get tim to scrimmage at the end of the sessions. The whole training session is about the drills and methods of transitioning from Defense to Offense or vice versa.
In US what we as coaches are being taught is that we divide the training session into warmup/loosening and after that we teach the players in small sided and extended sided and eventually finish with scrimmage.
I myself find the Spain method a lot more intuitive. It seems to me letting the players getting in the small sided activities will not teach them different methods of play. I think that drills will fix the technic of the players also. Repetition is the key in Futsal and creating self confidence for players by allowing them to be creative in their touches with the ball will eventually have a better result.
Futsal players must have good technic and a good touch. This will only be fine tuned with drills.