No leap necessary to open, sages are generally stationary unless being attacked. Sorc stuns, you take it. He gets a free force lightning, maybe 5k damage tops. Stun's up, you force camo. There's no root on you at that point. Now you close gap with +movement. No whirlwind, you interrupt it. He knockbacks, you break it. Saber throw to pop shield stun. If it doesn't crit and pop shield you melee with Crippling Slash. Shield pops, 3 second stun but he's slowed. Even if he cleanses it that means you're out of stun before he has gained much distance, you leap.
You're now in melee range with a Sorc wth no knockback, no stun, and no shield. If you can't win now, you're horrible.
If you're going to apply perfect tactical knowledge, timing and awareness to the sage, you might as well apply it to the marauder.