Maybe Tanjiro is a Breath of the Sun user by using the Dance of the Fire God, Breath of Water and some saying/asking that he's using Breath of Thunder. I'm curious about it and correct me if I'm mistaken. Is it possible to use other style under of their Breath Style? Take a look in the picture below.
Can Tanjiro use the other Breathing Technique?
It is not yet revealed in the manga but he was able to combine (2) different breathing techniques in the latest anime episodes so we can assume that he can be able to use the other breathing technique for the reason of
he is a Breath of the Sun user.
In chapter 68 of the manga
Rengoku Sr. declares that Tanjiro is a Breath of the Sun user, to which the youth responds with confusion. The older man suddenly pins the young Demon Hunter to the ground, causing Senjuro to plead for him to notice Tanjiro's apparent injuries. Rengoku Sr. tells his son to shut up, smacking him across the face. This enrages Tanjiro, causing him to knock the older man off of him. The youth demands to know why Rengoku Sr. is badmouthing his dead son and beating his only remaining son, causing the elder to demand if he is making fun of their family. Tanjiro angrily asks him why he would accuse him of such a thing, to which the Rengoku patriarch responds that it is because he is a Breath of the Sun user, noting his earrings and that it was written.