Hi Dan! Actually it was worse than that - you needed 2 x VC10 to teach formation! Each costing £10K per hour... The MELIN lemons were really short changed.
Teaching co-pilots who hadn't had the benefit of any jet formation time previously was something of a challenge - particularly at night!
BV will moan, but the old JP course (before all that Gp 1 Ph 1 drivel) turned out generic pilots with a full training background, who were then streamed FJ, ME or RW before AFTS. Even if they went to ME, that meant the training was in the long term memory, so if they went to a type which required formation flying as a normal way of life, it wasn't a huge shock to the system. It also meant that if they became BFTS or UAS QFIs at a later date, learning formation training was pretty straightforward.