I have never seen an Order Vampyrum turn into a Vampire Lord
You've never seen one period. Unless we assume the Count of Skingrad was part of that group.
I am talking about Physical power in a fight not what they control
True power is control. What physical power do you refer to? A person well versed in magic could destroy anyone. Vampire Lord or not, Lord Harkon didn't like fireballs to the face.
Vampire Lords aren't this super powerful, awesome, unstoppable force. They can be killed like anything else. They only survived this long, because they were silent for thousands of years.