Keep the colors of the textures more muted and realistic instead of colorful/cartoonish

This is a scary one for me!

Comparing aoe2DE vs aoe4, I actually prefer aoe2 because it's very easy to subconsciously comprehend what's going on because the units are all very distinct, the terrain is very distinct, buildings, etc. I think that aoe4 (and a few aoe2 maps, actually) is a bit harder to look at because everything isn't contrasted as much.

Ultimately, I think that a big part of this is the terrain, not necessarily the units, themselves. The units being distinct from each other makes a big difference, yes, but a huge blob of armies can very easily get lost in "muted"-looking terrain.

As a player, I'd probably favor the textures/colors of aoe2DE over aoe4 for the sake of playability

Just my opinion