Crimsonwood 2

I think if we fight a mage it should be a normal fragile non-magic guard mage.
Like Grog- hard to hit, but when you do hit a big chunk off the bar.
...
Really the mage would be the one with the LEAST HP.
Then probably the Ranger the Thief (dits have HP) and the Warrior.
In order from least HP to most.

I think a four boss battle would be awesome.
Through some platforms around and teleporter or two that ALL (including enemies) can use and we have one hell of a hoedown.

I agree with the mage having the least HP. Make it the hardest to hit too. Having platofrms like you said, would be a good idea to kill it. It would have the least HP, but it would be the hardest to kill (teleport + flying) and it seals + dispels. So taking it out first would be the best idea.

Then maybe the warrior could have the huge KB (25k), but have really short range. Also it would probably have the most HP and be the slowest.

The sin and bowman would have middle HP. Maybe the bowman could cast slow and darkness (lol 4th job moves), and had really nice range, so it wouldn't even try to get up close. Same thing with the sin, but the sin should have some pretty high avoid (probably something around dark cornians avoid). So that range would be the best to take him out.