Ixt said:
I recently mounted a Skink Chief BSB w/ Eternal Flame on a regular Stegadon with Sharpened Horns as a monster/beast hunter & cavalry/chariot interceptor. I haven't been able to find many other uses for him when kitted this way. I try to keep a Solar Engine Bastiladon around this build, which is usually successful since Stegadons tend to draw all the fire.
Some questions:
Does Unstoppable Stampede increases attacks for the crew?
Does a Skink Chief with the Sacred Stegadon Helm of Itza benefit from Sharpened Horns?
Does the Savage Beast of Horros extend to the Stegadon when cast on the Chief?
These all say, "the model...," and - with respect to the wording within Howdah Crew - seem unclear.
Your builds are very interesting, I'll have to try a few. I usually go for plain EOTG.
I think only the steg gets unstoppable stampede, I never use the rule. I'm not sure now because it says model and the howdah rule says it is all one model. I mean realistically its the monster - but rules are rules

In all honesty I would regard the monster as the model for all this confusing stuff
Steg helm: I don't think mounted characters can have impact hits off the top of my head
Savage Beasts of Horrors: Same as above, I'm not sure. I guess the best thing is to agree with your opponent for all these things.
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On the topic of the Skink Chief: I don't always use him too much, but he does come in handy sometime seeing he's only 40 points. I usually run him naked, either out in the open or even with a small group of skinks/skirmishers.
Because, don't tell anyone, but...
I like to use him as warmachine distractions (or regular confusions), to make my opponent paranoid. I you had a warmachine and you saw a Skink Chief out in the open (or in a small group coming towards you), what would you do?
"Why would a Skink Chief be out in the open all by himself? Oh no, that can't be good... he must be evil... shoot it shoot it shoot it shoot before he gets to me... oh no it was a trap..." I can confirm it has worked a few times. I mean it's another thing for him/her to think about. If another unit messes with your chamos or warmachine unit, there's this guy laying around. If he gets shot, good that could have saved some of you Saurus of even a monster. If doesn't get shot, run him into the warmachine.
After all, he is only 40 points