Haha you're right they are not the same profile. A starseer was also a wizard which is considerably more useful than the mild support this offers. I think calls of damage creep or super powered heroes is just fear mongering at this moment. Of the scrolls we've seen, half of them do less damage and even the ones do more it's mild at best. Besides I'm sure most skaven players would rather the warlock engineer be a wizard than have a few decent shots and a pretty mid support ability. /Shrug
New prosecutors The wings look better than the old design. Also, apparently abilities now have an equivalent to ward-saves where you can just ignore the ability on a 4+. Hopefully it only working on "non-core abilities" won't be too arbitrary a division.
Endless spells are basically summonable units now. On the one hand; I guess this is good. It allows them to do "regular" attacks, as opposed to mortal wound spam. Which opens up design possibilities. On the other hand; they can now be simply destroyed (in addition to being dispelled). And they aren't exactly sturdy (quicksilver swords has a mere 6 wounds, and a 5+/6++ save). So it's not like they take terribly much to be destroyed. Sure, any damage they soak is damage that isn't put into an actual unit. But it still seems a bit easy to destroy them like this. O, and needless to say, they don't benefit from any faction abilities or anything. Which is a bit of a shame. Could add some interesting flavour to have interactions with faction rules. Admitadly, allowing that would probably be a nightmare to balance Same for faction terrain. They can now be destroyed. And similarly, they also aren't exactly sturdy (8 wounds, 3+/6++ for the fyreslayer terrain).
Spearheads The spearheads themselves aren't that interesting, its just combat patrols for AoS. But they reveal some new (simplified) warscrolls. Mount attacks now have the "companion" ability. Presumably to make it clearer what attacks are buffed by artifacts and such. Cavalry is a keyword that exists now, apparently. They reveal the Magister on Disc's spell, and it kind of confirms magic is going to be the exact same dissapointment it's always been, as all spells shown so far have had no meaningfull changes (aside from the endless spells). The magister is better at melee combat than it used to be for some reason. It's ranged attack is still essentially useless. Which is a shame. Had kinda hoped that the new skaven model indicated GW had realized that support heroes need to be given something meaningfull to do besides their 1 spellcast/ability-use per turn, and that melee attacks on a support hero are wasted. But I guess not.
Twists & battle tactics. Honestly, it seems a bit much? Having the effects be better than your average spell/ability on a random minor hero seems a bit weird.
Terrain rules Models can now jump off cliffs. Unclear if there is going to be fall damage. Only faction terrain can be destroyed, which feels odd. Other than that we seem to get 40K rules regarding LoS. And some terrain pieces can give you a +1 to casting on a D3 roll.
terrain changes seem smart, seems like it cleans up a lot of the nonsense while also being more impactful.