8th Ed. are champions worth it??

Simply put, a vicious hero or lord will kill 5-6 Saurus or TG in a round of combat. With a champion all the wounds go on the champion and saves the unit 4-5 models. This keeps you steadfast longer and saves you models for the next round.

If you are running a life Slann, you can abuse Regrowth to revive models in a unit, and the first model revived is the unit champion meaning he can accept and issue challenges again.

Some characters can force a unit to accept a challenge and if they do this to the Slann's unit and he has no hero/ or unit champion to accept for him he will be stuck in a challenge with a combat lord and will be in serious danger.

For skink skirmisher or chameleon skink units it is a waste of points. The extra BS is not going to make a difference because with skinks you are relying on jungle poisons to do the damage rather than the BS and to wound. In combat, skinks are going to lose to almost anything so again the skink champion is rather useless here. A cohort champion could be useful if you dont have a lot of skinks in the unit and want a cheap sacrifice to a hero/ lord to save back rank skinks.


TLR Combat champions- yes, Ranged champions - no

 

The question is why did you bother challenging? If you had not, you would have simply had more attacks from the rest of your unit at the exact same WS and S so more of a chance to make that would you needed. If the BT forced you to challenge, then if you didn't have the skink champ there you would not be in a challenge so would have had the same benefit of extra attacks from more models in base contact.
Of course, had you not been lucky, being in a challenge would have stopped your unit being being killed for a round as mentioned, but in general they are better off staying back and shooting anyway except skrox units.