The blue tilapia are African cichlids (Oreocromis aureus). This means that typically they are a very aggressive family of fish. If you have ever raised African cichlids in an aquarium you will understand what I mean. I used to raise many different varieties. I have not raised the Blue Tilapia in an aquarium so that limits my first hand observations of this species however I can draw some conclusions. If you confine a lot of them in a small space (i.e. a truck) and then haul them several hours... they will fight... ALOT! They will be stressed when they arrive to your pond and will be disoriented. Add to this the stress of different water temps and pH and you should expect to lose a few fish to predation as well as simple stress. If they are half the size or less of your predators then most of them will become expensive sushi for your predators. Holding them in a pen will save them from predators but they will still be trying to kill each other. JMHO.
My advice is to buy them larger than your predators can eat, release them into your pond and let them eat your FA after they recover.
seantOH
