A commitment to taking the gospel to the ends of the earth will involve you in sacrifice. Yes, there will be good bits, but much of it will be hard.
God is at work around the world, building his church and calling people from everywhere to be involved in the work of cross-cultural mission. If your agency can see no further than mobilising Brits for mission work, then, frankly, you are out of step with what God is doing. You might want to consider shutting up shop.
The thing is, when we concentrate on measuring deliverables such as finance and recruitment, we can ignore the elephant in the room – what exactly should the agency be doing in this day and age?
Mission agencies face a crisis and they cannot simply mobilise their way out of it.