Sam2, I don’t actually have anything invested in either picture. However, I don’t consider Titus’ arch as any proof, at all. It was erected after he died. The artist probably never saw the Menora. Does it have a depiction of the full count of Gevi’im Kaftorim and Perachim?
Some say that Titus got a fake Menora. But, it was probably a look-alike, anyhow.