Sorry wrote that in a hurry yesterday
my thinking is this
Anakin decided to join el sid, & then goes to mace to say that the chancellor will not give up his powers (never mentioning his true identity)
then they go and get the shock of their lives
(I'm just looking for any excuse to remove the -
Mace: A sith lord?
Anakin: yeeesssss. The one we've been looking for?
Disastrous wooden Dialog