Other factors involved mate. You can't just match valves on the current draw at the grid.
I tried getting an answer out of Mesa ages ago and got nowhere. They've heard it all before, you can't fool em.
Watford Valves in the UK offer valves matched for Mesa amps. But charge nearly as much. You may as well buy Mesa.
I did lob some El34's out of an old 800 in my Mark V for half an hour. Just so I could be sure I wanted to go the EL34 route. Ultimately I bought some Mesa valves to do it and put the EL34's back in my 800.
Truth be told, my original valves are good, I think there is something other than marketing talk to Mesa's claims.