Anyone who has travelled as a staff pax on BA when the gate staff are IB will understand that the IB employees seem completely unable to adapt to methods used by a different carrier.
On a less than full flight they will only issue boarding passes to the staff at the very last minute, despite there being plenty of seasts available. The passes are printed then held back.
1/. You get staff waiting at the gate area which never looks good.
2/. One of the golden rules of gate operations is 'get 'em on' as soon as you can - why on earth hold back?
Why purposely hold back those boarding passes when you know damn well there are seats available.
They also seem totally unable to recognise, or refuse to do so, the other airlines seniority system. Why? because that's the way they do it - unbending.