The rule is fair. When you are capable of doing a 3Axel, it's silly that you HAVE to still do a 2Axel in your SP after completing a 3Axel+2Toe combo.
3Axel+2Toe is more difficult than 3Lutz+3Toe, yet it's worth less points under the current CoP. Think about it.
3Axel+2Toe is more difficult than 3Lutz+3Toe, yet it's worth less points under the current CoP. Think about it.