Bavel = Balal?

I wrote in a previous post about how, on the line of Talmud about splitting one's learning into thirds of Tanach, Mishna, and Talmud, the Tosafot defend the practice of their day of learning only Talmud by holding that the Babylonian Talmud has a mix of all three. I theorized there that they further defended this practice in an unrelated aggadata which they state that the sages of the Talmud were sometimes not experts in Tanach, an understandable statement if the Tosafot thought the sages also never really held to the "thirds" approach.

In this post, I want to point out their proof that the Babylonian Talmud is "mixed", which they adduce from the Talmud Sanhedrin 24a. There, we have this statement:

What does [the name] Babel connote?  — R. Johanan answered: [That the study of] Scripture, Mishnah and Talmud was intermingled [therein].

Where does Rabbi Yochanan get this idea to make a folk etymology from Bavel (Babylonia) to Balal (mixed)? Straight from the Tower of Babel story, where the verse does it itself (Genesis 11:9):

ט עַל-כֵּן קָרָא שְׁמָהּ, בָּבֶל, כִּי-שָׁם בָּלַל יְהוָה, שְׂפַת כָּל-הָאָרֶץ; וּמִשָּׁם הֱפִיצָם יְהוָה, עַל-פְּנֵי כָּל-הָאָרֶץ. {פ}
9 Therefore was the name of it called Babel; because the LORD did there confound the language of all the earth; and from thence did the LORD scatter them abroad upon the face of all the earth. {P} 

At this point we should note that Rabbi Yochana was using the folk etymology to mock the Babylonians. Yet Tosafot use it as an advantage to them, that they get all three studies in one book. It seems obvious that "balal" in the Tower of Babel story is a bad thing. They were "confounded". Talmud learning, if things are "balal", is not very successful.