It doesn't matter what anyone thinks here! It doesn't matter what the bmiCC think. It doesn't matter what the BACC think reference seniority.
It does matter what BA thinks.
They think if bmi pilots join the msl on bmi doj then they will be entitled to the respective paypoint. That means quite a few pilots will get significant rises in basic pay.
BA are on record for all to see that they will not permit this.
Unless of course BA pilots accept a reduction in Ts and Cs to cover the costs.