No let's not. The question is valid because you CT's are always quoting Arnold about Lee being in the second floor lunchroom and Oswald as saying he was on the first floor. So, again, who do you believe? Arnold or Oswald?
Your question would possibly be valid if we had a full first hand verbatim account about what Oswald and Arnold really said. Context matters and since we only have scant second hand information to deal with, there is nothing valid about your question.
Both Oswald and Arnold could well both be correct, for one very simple reason; we know that Oswald, at some point in time, was in the 2nd floor lunchroom because Truly and Baker saw him there. However, his being there 90 seconds post shots does not preclude him being on the 1st floor earlier, to see Jarman and Norman enter the TSBD at the back, near the domino room.
So, ask questions, by all means, but provide context to them before you do.