Palp, Vader, Sion, Nihilus and...

Before i use sith trooper, but bcause lately people change sith trooper to the general.. i follow the mass lol

I'm assuming anyone who is voting Trooper just hasn't seen this team with Thrawn or Wampa. This team with Trooper is non existent in arena top 100.
Wampa all the way especially at 7* and Thrawn after that.

Sith trooper is so favored because he (WAS) the only sith tank before sion. The mindless throwing him in part is 100% true. His abilities also look great on paper (omg he ignores protection that means I can ignore 90k of GK protection) The fact that ignoring protection doesn't mean anything if you can't outright kill someone is not something a lot of people think about. So yeah, basically he is a sith tank, with a great looking paintjob that gets ruined as soon as you take it on the road.
Thrawn is great for all the above mentioned reasons. Mostly a uber fast, uber disabler char that can swap his TM into slow sith titans.
My choice should have been other, since nobody mentioned MT. Undispellable pain with palp shock smells like victory to me.

none of the above, yet all of the above. sounds weird huh ?
well until treya is available, you'll need use different guys to beat someone with better modding.
zHan beats faster EzPz+Vader teams and rex teams, MT very effective vs jRey if you struggle (though you shouldnt), zAV effective vs jRey and AV, Tarkin effective vs Titans.
as you notice, i mentioned a previous meta toons. you should have them high enough. Mix-And-Match to use minimum amount of fights.
funny thing is that vs better modded teams, SithTrooper wont give you much actually, and a simple Han would be so much more effective. but on defense, its probably SithTrooper that will be the best option, because it will allow you to beat similiar/worse modded teams, and will be much more effective than Han (unpredictable)

Your best tank, with pre taunt counting extra

SiT if you don't have Sion's zeta (which you should if you are running him in arena), Thrawn if you have it.