The first sign of trouble and BA will stick them all on a standalone, basic TUPE fleet to whither on the vine. it really won't be worth BAs trouble to offer anything more.
This view demonstrates breathtaking naivety. Having bmi pilots stuck on a standalone TUPE fleet will generate very significant problems for BA and BA pilots. It will also build in massive extra cost for BA as they will have to maintain a very different contract of employment with a very small working group. You can be sure that any disgruntled group such as this will organise themselves. Maybe they could offer BA a 40% reduction in the crew cost across the long haul fleet. It would be a massive thorn in the side of BA pilots. Believe me, no BA pilot in their right mind should wish for this outcome.