No idea, the only oval ball where I’m aware of a reason for its dimensions etc is the NFL ball which is more pointed to enable it to go further and without going end over end. Back in the early days of U.K. NFL coverage there was a feature on this on the C4 weekly show with NFL’s only U.K. representative at the time (and later C4 commentator) Mick Luckhurst doing the throwing, doing ok with the NFL ball and looking a fool with the rugby ball

Apologies for adding colour to the discussion and no I don’t know mick luckhurst personall