I don't think Barrera could make it into a war and that would be his only realistic chance since he won't be able to outbox or one-punch KO Loma.
I do agree with you that that is the only way MAB could realistically win the fight, but why do you think he couldn't drag Loma into that kind of battle?
Simply because i can only see Lomachenko getting involved in that if he's losing and has to make something happen. It's not that there wouldn't be any good exchanges, but a war? Nah. Loma likes hitting, and moving out of the way and getting in position to land more.