First Cater to AOE RTS community then think about bringing in other people. If your Product aligns more with the mental model of the core audience there will be less disconnect in End user experience.
The core audience will then bring other people similar to them. You cannot please everyone, first, any designer should understand that. (Designer in video talks about designing for a larger wider audience, great to add to portfolio and resume, but kills the product for core user base)
Increasing the size of weapons does not result in unit visibility, what you do is make the Silhouettes distinct (weapons are part of the silhouette). This is a core principle of any RTS game, just check out your own AOE 2 DE and how each cavalry unity has a very different silhouette Human eye always go for the overall form, colour, then for textures and other minor details (weapons should not be treated and individual entity, but should be considered as part of the unit).
The long bowmen look great but looks like they shoot toilet paper rolls, Swords and shields are looking bigger than the units itself. This tells the user, that they are infantry, but does not help in making distinction between an Indian or English or what Infantry. The units are bigger than trees, more like in a 4X game like CIV VI.
Look at the Delhi Sultanate Trailer, Indian troops looks same as English, but one has to then pick and look at their helmets to tell who is what faction. In DE, the Indian units have different silhouette than the English. The problem in AOE 4, your silhouettes lack horizontal elements to make up a distinct form. The champion has a different Sword Stance in AOE 2 from a Man at Arms and that form changes the vertical and horizontal aspects to form a distinct outline. Their Hand stance, foot stance and movement animation communicates very strongly.
Same Mistake Relic studio did for DOW 3, instead of catering to Warhammer and RTS community you went for Esports gameplay and other communities who doesn’t play RTS games but, thought by showing a cool Titan (Robot in your game), people will come play it. RTS community is different from Esports.
People already have Esports game and Mech games so why will they leave that and suddenly play this?
SC was made as a RTS game first, Esports originated from it organically, you cannot enforce it then you will end up in a game for nobody.
UX is not about UI, UI is a very small part. Play experience, visibility, colour, geometry, performance, tech, server performance everything contributes to UX.HCI is just a small branch in that.
Hope you guys can improve the game and deliver the best RTS in the market, keep up the good work and keep growing.