Understood, and this was something we kept in mind. Basically, it works like this:
When the print run for the 32-page adventures run low, we look at compiling them into a hardback (as well as being able to update them, this also reduces the number of stock units we have overall, which both retailers and distributors like a lot).
However, three adventures is not really enough for a hardback, so if we do not have enough, we add a couple more.
That is the only reason we do this. If, for example, we were to compile Reach Adventures, it would be Reach Adventures 1-5, and no new titles would be added to it. The intention is to compile things into a hardback, and new material is only being added because there is not enough adventures to do that.
The alternative would be to release Adventures 4 and 5 separately as softbacks, which would mean either Adventures 1-3 go out of stock for a couple of years OR we reprint them, which would mean we then have to wait until they all go out of stock again, and basically nothing gets done. Ever.
Not brilliant, but that is where we are coming from.