Question

Hello and blessings! 
I saw in a few places things that I don’t fully understand regarding Passover and Sukkot: 
1. In Torat Kohanim, Emor, section 12:2, it says:
“[2] ‘This is the festival of Sukkot’—this one requires a sukkah, but the Festival of Matzot does not require a sukkah. But surely this could be derived logically! If this festival—which does not require matzah—requires a sukkah, then the Festival of Matzot—which does require matzah—should all the more so require a sukkah! Therefore Scripture says, ‘This is the festival of Sukkot’—this one requires a sukkah, but the Festival of Matzot does not require a sukkah.”
 
What is the initial assumption here at all? 
 
2. What reminded me of this exposition was Rabbi Dov Lando, who at the “Ritkha De-Orayta” gathering that took place yesterday (around minute 45 on YouTube) argued that according to Rav Acha bar Yaakov in Pesachim 120, who holds that the commandment to eat an olive-sized amount of matzah on the first night of Passover is Torah-level only when there is a Paschal offering, there is never any Torah-level obligation to eat an olive-sized amount of bread on Sukkot, because this is learned by analogy from the first night of Passover—and on Sukkot there is never a Paschal offering, so it is impossible to derive by analogy an obligation to eat an olive-sized amount. (I hope I understood him correctly.) They argued with him there a lot and raised counter-arguments, but he did not accept them (and even started arguing with them about the rules of analogy, but I’m not very knowledgeable in that area).
 
Is there room to say that Rav Acha bar Yaakov does in fact accept this analogy? 
 
I’m sorry if the connection between the two sections isn’t clear, but I have a feeling I’m not managing to formulate clearly that there is a connection between the questions.