The jumping Jupiter scenario is usually associated with the Late Heavy Bombardment, which is half a billion years too late for the age of the Moon estimated by

The jumping Jupiter scenario is usually associated with the Late Heavy Bombardment, which is half a billion years too late for the age of the Moon estimated by OP. But of course there are disagreements about when Jupiter did its thing. There's a lot of variance in "Mars-sized", so I wouldn't count on an easily noticeable mass-balance match. Mars, Mercury, and the Moon are all very small compared to Earth. Earth is more massive than all of the other rocky planets and the Moon combined, and yes, that includes Venus.