Prince Vultan of the Hawkman and King Leonidas - separated at birth

I was watching Flash Gordon today and I was struck by Brian Blessed's the over the top portrayal of Prince Vultan of the Hawkmen and it's similarity to Sean McGuire's over the top portrayal of King Leonidas in the 300 spoof, Meet the Spartans.

Brian Blessed as Prince Vultan of the Hawkmen.

Sean McGuire as King Leonidas

Sean McGuire as King Leonidas, but intense.

Separated at birth? Related? Is it just the beard and the shirt free outfit?