I know I will be corrected if I am wrong, but I vaguely remember reading that the reason
VB got away with paying the E-170/190 drivers less than the B737 drivers in the current EBA, was because they agreed to paying more for a larger type.
If so, does that mean that there is already provision for more pay for the A330? Unless that was specifically for the B777 & by using another type (A330) they get around that provision, just as they got around it with the B777 by forming a new company.