What's probably happened is they were topping up 967 & 968 Troops, realised the numbers were such that they could all be lumped into one troop. Those initially assigned for 967 were then put in 968. As 968 already existed & 969 was probably beginning to be loaded up, it would be easier just to cancel 967.
Hope that makes sense, I need a lie-down as I've just confused myself.