It seems to make perfect sense to me. Apparently the RN as a whole is underborne with Lts and has too many 2 & a Halfs. So fill the gaps.
It is not unprecedented, in the late 90s the Junglie community has 4 Aussies flying with us as their Squirrel programme had collapsed and they were consequently overborne.
I think there may be a problem for budgets. Already the RN has factored in the savings created by gapping. Thus we no longer have the money to fill all the gaps*! I imagine there would be some interesting TLB to TLB chats as to how the RN might fund RAF aircrew when they have no money to do so.
*Before I'm challenged on the source of the budgetary comments, it is legit.