One problem is that Arrows/Fleches are an oddball event format (in randonneuring terms) and cannot be dealt with systematically.
They probably could, just it would be a system specific to arrows.
It would need to record team composition, have an acceptable threshold of time difference at controls (Queues and taking longer to pick from the menu at mcdonalds) and be able to determine how many riders in each team reached the finish control.
It would also need the 22nd hour rule and location and distance at 24th hour if not the finish control rule as well.
As it needs to work out shortest distances it could link into Google's routing (costs $$$) and do route agreement automatically and spit out Brevet cards from that.
There would be limited advantage to AUK for that as there's only 2 a year.
However ACP has apparently over 700 a year to handle, they would probably gain quite a bit by implementing some sort of systematic assistance.
ACP's lack of rider UIDs would be an issue of course...
If I could be bothered
I'd attempt to knock one up as a training exercise for myself.