I’ve just tested them in the original AoK. It takes a Scorpion 10 shots to kill a Knight and 6 shots to kill a Light Cavalry (both players starting in Castle Age, so with Feudal Age upgrades). Compare this with 5 shots to kill a Long Swordsman and 3 to kill a Crossbowman.
Interestingly, Scorpions benefitted from Archer attack upgrades in AoK. I’d forgotten that. It might have been a mistake, since it’s not mentioned in the descriptions of the upgrades, and was removed in The Conquerors.
someone didn’t read the manual
Ah, whoops, good point. Having remembered that DE comes with a pdf of the AoK manual, I have now read it…
There was a screenshot of it right in the middle of the thread 
Nah onager is better here (not even considering that you can further upgrade onagers to SO). Onagers will flatten scorps before scorps kill your infantry.
The original intentions of the developers mean nothing, this game is heavily based on sheer randomness, many of the mechanics are unexplainable, unlike many other RTS games, and that’s the beauty about AOE.
You basically over-rationalized the role of Scorpion based on a hint from 1999.
Siege is one’s way to comeback into the game, a strategic moderator to the deadly death-ball of Archers, Knights do not benefit equally from mass and are much harder to train (cost and more importantly the fact they’re an exclusive Castle Age unit rather one that scales from Feudal)
You don’t need a moderator in this department, Knights are counterable by the time your opponent gets to mass them. And on top everything you got Monks which are a fascinating tactical feature by its own.
Regarding the infiriority of Scorps to Mangonels, they’re different units, similar in many aspects yet distinct enough to justify their current strategic form.
Coming from the person who worships AoC Arabia and then says the intentions of those devs are meaningless? And then hates on lots of the “gimmicks” and other features, before saying that’s what makes AoE beautiful? 
Scorps are excellent units stats wise. Cost effective Vs one of the widest ranges of targets in the game.
The problem is their clunkiness.Scorps need to be massed to reach that cost effectiveness, but when they’re massed their counters absolutely obliterate them
They’re probably the hardest countered unit in the game by their counters when massed . It’s an inherent weakness due to the combination of abysmal siege pathing, awful speed, big hit box and low hp.
I would give scorps higher speed for one (0.65 to 0.7) They’re a lighter siege weapon than the mango line(20%less hp) and their 8% higher speed doesn’t fully reflect that.
But then I’m biased because I think a load of units need speed increases (militia line, battle ele, rams) or projectile speed increases (mangos) due to the faster nature of the game and better micro
That’s one of the big points with them. In small numbers they only work decently vs archers and cav archers as they need to be massed and are hard-countered by scorps.
Scorps also don’t work that well against infantry in low numbers actually.
That’s why I though: “What about if scorps would actually be useful in lower numbers against low numbers of cavalry? Not to oblitterate them, but to force them away and potentially even damage them a bit in the process.”
That’s why I proposed lower range (potentially taking away the minimum range also) but some bonus damage - also potentially only damaging 1 unit instead of multiple (better rof in the exchange).