I wanted to share these two ideas that I came up with recently that could potentially be added to the game in the future, where the [Canoe] could be added to the game as a trainable unit and another unit by the name of [Flare Archer] can replace the [Trebuchet] for some civilisations.
(1) The [Canoe] is an untrainable warship that was introduced in “Age of Empires II HD: The Forgotten” (2013) and it could replace the [Galley] for the Aztec and possibly for the other Pre-Columbian Civilisations as well, where they will serve as weak warships that has the advantage of overwhelming other enemy ships through their numbers. When reaching the Castle Age these ships could be upgraded to the [War Canoe] and finally to the [Sturdy War Canoe] in the Imperial Age. The [Sturdy War Canoe] could as a ship possess a similar strength to the [Galleon], however, the trade-off is that they will have less hit points but is much more cheaper and can be trained quicker.
Another user by the name of @RomasterChief posted a similar suggestion about two years ago (2020 I believe) where the Aztecs could be given canoes (Suggestion - Canoe boat for the Aztecs).
(2) The [Flare Archer] could replace the [Trebuchet] for some civilisations in the game and serve as a long range siege unit that specialises in destroying walls and buildings. They can be trained from the [Siege Workshop] in the Imperial Age. The range of the [Flare Archer] will be somewhat shorter than the [Trebuchet] and they won’t deal as much damage individually, but they will be cheaper, have a faster fire rate and can be quickly massed in numbers. Another advantage that they could have is that they don’t have to pack and unpack like the [Trebuchet], however, they will have a slow movement speed and have to be escorted by other military units in order for them to survive.
The [Flare Archer] will only be good against buildings and other Flare Archers, including Trebuchets, but they will perform poorly against every other military unit type.
I was inspired by the [Arrow Knight] from “Age of Empires 3” when I came up with the idea of the [Flare Archer] which serves as a long range anti-building unit for the Aztecs in that game. The name [Flare Archer] might sound a bit silly at first but people may learn to appreciate the name over time. According to the Wikipedia the word “Flare” is probably related to the Latin Word “Flagro” (I burn) and the Norwegian “Flara” (To blaze) but the English word “Flutter” seems to predate it, so the name “Flare Archer” does make sense for a unit that will set things on fire.
And yes, I know that the Bow and Arrow did not rival the range of the Trebuchet in reality, but I think that it is important that there is at least one siege unit in the game that represents both the complete and partial lack of siege weapons for some civilisations in reality. Adding a siege unit that fires flaming arrows from an absurd range like the [Flare Archer] could be a necessary historical inaccuracy for the game and a better option than giving some civilisations like the Pre-Columbian ones access to the [Trebuchet].