Non mirrored JBL 4312...

another words, the woofers are symmetrical, but tweeter and mids are on the same layout.

You could try to swap the midrange and tweeter with each
other. I know the cutouts are different but it could be
done.

Also, a lot of the early JBL speakers were made to sit
upright OR on their sides. If you placed them on their
sides, it wouldn't matter because the mids and tweets would
be in the same location. Low frequencies are non
directional, so it doesn't really matter where the woofers
are on the cabinet. In this configuration, one woofer would
be on the outside and one on the inside.

You could also just toe in one speaker a little more than
the other to align the tweeters with the listening position.
It will look kinda funny, but would accomplish the same
thing.

You start swapping drivers around and you'll never sell them. Just leave them alone and hope for the best. I highly doubt anyone who buys those speakers would hear the difference anyway.