Is there a way to order tracks so that video tracks appear above audio tracks (V1 over A1, V2 over A2 etc?)

No. Only V2 over A2, V1 over A1 with mixed audio track.

Merlimau wrote:No. Only V2 over A2, V1 over A1 with mixed audio track.

I don't understand the "No" and the "Only". Are you saying that beyond 2 video tracks and 2 audio tracks, I should not expect consecutive tracks to be Vx over Ax with mixed audio track? That seems to be what I'm experiencing. The organization seems to fall apart at some point.
I'm wondering if this is a glitch or am I doing something wrong or is my thinking incorrect?

Thanks for the feedback.

This is a bug. Sorting of mixed audio track is correct up to 3 video and 3 audio tracks. Beyond 3 video and 3 audio tracks sorting gets wired. I opened issue: https://invent.kde.org/kde/kdenlive/issues/220

Solved with upcoming 19.08.2.