Even if we don't have 100% confirmation on the seat of Moses the point is clear in the text. Its also obvious that Jesus was not teaching anyone to keep Rabbinic interpretation. One merely needs the read the following verse to see just how much Jesus disagreed with Rabbinic logic. Jesus didn't even agree with them being called "Rabbi". Here are a few examples:
4“They tie up heavy burdens and lay them on men’s shoulders, but they themselves are unwilling to move them with
so much as a finger.
Obviously in reference to their version of the oral Torah
5“But they do all their deeds to be noticed by men; for they broaden their phylacteries and lengthen the tassels
of their garments.
Overt spirituality, insincerity
6“They love the place of honor at banquets and the chief seats in the synagogues,
7and respectful greetings in the market places, and being called Rabbi by men.
8“But do not be called Rabbi; for One is your Teacher, and you are all brothers.
9“Do not call
anyone on earth your father; for One is your Father, He who is in heaven.
10“Do not be called leaders; for One is your Leader,
that is, Christ.
11“But the greatest among you shall be your servant.
12“Whoever exalts himself shall be humbled; and whoever humbles himself shall be exalted.
The entire authority structure is being challenged here
13“But woe to you, scribes and Pharisees, hypocrites, because you shut off the kingdom of heaven from people; for you do not enter in yourselves, nor do you allow those who are entering to go in.
14[“Woe to you, scribes and Pharisees, hypocrites, because you devour widows’ houses, and for a pretense you make long prayers; therefore you will receive greater condemnation.]
False humility and neglect of the widow's
27“Woe to you, scribes and Pharisees, hypocrites! For you are like whitewashed tombs which on the outside appear beautiful, but inside they are full of dead men’s bones and all uncleanness.
28“So you, too, outwardly appear righteous to men, but inwardly you are full of hypocrisy and lawlessness.
Here Jesus is calling the Pharisees "lawless". So are we really supposed to believe that Jesus commanded his followers to follow "lawless people"???
Of course not! The command was pertaining to Mosaic authority. Pharisees were teaching both Moses and their own doctrines.