Because ultimately, it's the MD that has the duties of making sure that business is running smoothly/efficiently. I have no doubt if the MD is seeing a pay increase, they will be scope for ATCO pay increases in the near future.
NQY is expanding, slowly admittedly, but it's expanding. This means more workload, this means demands for higher pay. The scale should trend in the ATCO's favour in the near future. Also remembering that pay levels in the Cornwall area are naturally lower.