I know a guy who is not a good striker. His grappling skill can help him to deflect most of his opponent's punches into underhook, overhook, or head lock. He is also not a good kicker. His grappling skill can also help him to capture most of his opponent's leg. After he had wrapped his opponent's arms or captured his opponent's leg, his grappling skill can take his opponent down from there and his weakness (not a striker) will no longer be an issue.
People may say that a MT guy's roundhouse kick could break your arm. To me, if your opponent breaks your arm but you crack his skull, it will still be a good trade off.
Student: Dear teacher! I need to fight a MT guy but I know nothing about kicks.
teacher: You may not know how to kick but do you know how to take a kick?