One of the best parts of AoE III is for sure artillery. Cannons are really strong. When AoE III cannons defeat enemies, the corpses even fly back. The stronger the firepower, the further away the corpses go. AoE IV (medieval) artillery can’t be that strong, but surely it can be stronger than how it has been done in AoE II.
In AoE II gunpowder is mostly underwhelming. Even in post-imp. it’s not obvious a gunpowder civ. will want to massively go for it. The bombard cannon, the game’s most expensive unit!, is a pure counter unit, completely unworthy (too frail and expensive) to be used against non-siege units. Hand canonneers aren’t even always preferable to (fully upgraded but otherwise generic) arbalests to deal with infantry, which is really weird (see Hand Cannoneers bad state confirmed).
I’d like to see in AoE IV at least specialised gunpowder civs., like the Chinese, to train cannons which are capable to do actual damage in the way of being able to one-shot most infantry units.
Right now, in the published game footage, this doesn’t seem to be the case. Cav. archers did fall due to gunpowder, but it’s unclear how often they already got shot at.
Truly strong gunpowder (against non-cav. units) can be balanced through different means: a long reload time (AoE II & III); a huge elephant-like cost and training time (AoE II & III); different pop-space (AoE III; also already AoE II with the karambit warrior); or even maybe a training limit (eg no more than six heavy cannons at the same time). At last, it’s no problem if some rare, strongest infantry units, can survive one cannon shot, as that’s already the case in AoE III.
At last, it’s noticeable that AoE II gunpowder that’s already available in Castle Age is used and is strong. So gunpowder in AoE IV should imo also be available with also beefy stats in Castle Age - at least for specialised gunpowder civs like the Chinese.
Edit: Originally I was only thinking about the civ. identity of AoE IV Chinese, which is amongst others “strong gunpowder”. But considering AoE IV wants to be historically accurate and that Chinese apparently didn’t have at that period of time strong cannons, I have to adapt. If there’s another gunpowder-heavy civ. in AoE IV which also had at that time of history strong cannons (be it at the launch of AoE IV or in a future DLC), then I’d like it to have strong cannons which feel much more AoE III-like than AoE II-like.
Perhaps the French? First their presence in AoE IV is like 99 % sure and secondly cannons significantly helped them win the Hundred Year’s war after all. According to a sourced sentence in wikipedia, “The French artillery developed a reputation as the best in the world”.