My (science-based but certainly not hard sci-fi) world is basically a large island run by a couple of mad billionares. They have each built an army of aircraft armed with cliche "futuristic" type weapons such as rail/coilguns, lasers, plasma-bolt weaponry, and both charged and neutral particle beams. Battles happen at both low and high altitudes within the atmosphere.
Lasers are primarily used against smaller craft.
Railguns, plasma weaponry, and particle beams are used against larger ones.
They have the technology to create large magnetic fields to deflect plasma and charged particle weaponry, but the destructiveness of these weapons keeps them in use.
How can I justify the use of so many diverse types of weaponry?