None of the kings of England have a legitimate claim since the usurpation in 1066 by William of Normandy.
With respect, not so!
At the time of The Conquerer, the island was all divided. Edward had no direct heir and designatedWilliam as his heir. Harold took exception hence the Battle of Hastings. William consequently “united” most of the kingdom and founded the beginning of the modern day England.
Your argument could also be made to allow the kings of Denmark to have a greater claim too.