[Executor]

Really? More slots is worse since you spend extra gems?

Adons still are SC from turn 1. The change of 1 enc doesn't alter that. Saying that is just silly. You can still expand perfectly with them though if you happen to see a heavy cavalry province or one with a lot of stuff in it god forbid you'll have to use something other than an Adon to take it, that is, before you manage to get a girdle of might on turn 15 and have zero enc again... In the meantime you just may have to use regular troops.
I don't get why people are obsessed with zero enc. You don't need zero enc to use Adons, or their regular sacreds for that matter. With E10 they will have enc 2 which is perfectly acceptable.
Research malus? What now? Who in their right mind would keep Adons in a fort researching anyway?

I don't see how having teleporting Adons are a problem for that matter either.

Kohen Gadols are not as dangerous simply because they are unequipped Adons, with more or less the same stats. And they don't really have more magic until you hit blood 9 or want to use a communion a bit more effectively though not efficiently.
The thing is, Kohen Gadols need quite a few more items than Adons. Their do have a better base enc by 1 but their armor sucks, their weapon is terrible and they don't have an extra gore attack. They also have slightly worse stats, lower attack, defense and protection. And the HP difference, that's 2 HP.