Ghasts spawn excessively without pigmen

On an (aternos) Minecraft server i had used a command to avoid pigmen because the pigmen were always aggravated if you used a weapon (servers fault, not game) and a huge amount of ghasts were spawning, about 3 or 4 times more than usual. I  used the command /tp @e[type=minecraft:zombie_pigman] ~ -255 ~ in a repeating command block to deal with the pigmen.