Here's a random thought:

The MEC is obviously divided on the merits of this agreement.
I hate to see our union go through this divisive exercise. We need unity.
There might be a way to get a 19-0 vote.

ALPA is always accused of mounting a "sales job".
Whether you agree or not, a lot of pilots perceive that as somehow unfair.
That sales ritual is the source of nearly all the acrimony and divisiveness.

One option would be to simply empower the rank and file:

Send it out without the MEC formally recommending a yes or no vote.
Let the line pilots read it and decide for themselves.

Individual ALPA officials can opine to their hearts content.
Just refrain from activating the "machine" this time.

Small "d" democracy. Writ large.