I've completing several Jurassic-level challenge modes, and tornadoes have always been the worst part of that game mode. They just rip down all of your fences as if they were made of toilet paper. (Precious, precious toilet paper.) You can't plan for them, and you can't even do anything to mitigate their fence damage. Plus, they're clearly programmed to seek out buildings and destroy as much stuff as possible.
Please, make tornadoes do less damage to fences. Even the weakest fence is still made of heavy steel cables, so they should be able to withstand at least one tornado. Then, if you were dumb enough not to repair your fences when the next tornado comes, they can be destroyed.
To compensate for the decreased level of challenge, I suggest making dinos even more difficult to manage, and/or making guests harder to please. (Contracts are already enough of a pain in the ass, but at least they're manageable.)
Please, make tornadoes do less damage to fences. Even the weakest fence is still made of heavy steel cables, so they should be able to withstand at least one tornado. Then, if you were dumb enough not to repair your fences when the next tornado comes, they can be destroyed.
To compensate for the decreased level of challenge, I suggest making dinos even more difficult to manage, and/or making guests harder to please. (Contracts are already enough of a pain in the ass, but at least they're manageable.)