By overriding the GameMode::StartPlay you can manually dispatch the begin play methods.
void AGameModeBaseC::StartPlay()
{
//Ensure Formations Will begin play Before the Characters!
UWorld* World = GetWorld();
if (IsValid(World))
{
for (TActorIterator<AEnemyFormationActor> It(World, AEnemyFormationActor::StaticClass()); It; ++It)
{
AEnemyFormationActor* Actor = *It;
Actor->DispatchBeginPlay();
}
}
//Dispatch Super:
Super::StartPlay();
}