I won't overreact to this first because Oviedo is not a difficult opponent for Real Madrid and also 2 goals came in the final minutes of the match to ensure Real Madrid won 3 goals and I think overall Real Madrid's performance has not been that impressive, if they meet a tough opponent I am pessimistic that Real Madrid can overcome them.
So Real Madrid has to score 10 goals to impress you? What if we look at the Barcelona vs Levante match? Will it also make you unimpressed with Barcelona? Yes, Real Oviedo is a bottom team, but so is Levante, but they also played with 11 men. Yes, I understand that you are quite skeptical about the quality of Real Madrid's performance, which you think is still doubtful, but one important thing is that Real Madrid shows a much better picture of development than in the previous season. Their midfield area currently looks more promising after Arda was fully trusted by Xabi, they really have the capital to face tough teams.