I think First person viewing is what has been missing from Age of Empires. It gives me jitters just imagining how AoE would look from first person view.
A place where you can be a unit and go to war, those war horns, sounds. Imagine a server ( for example an FFA regicide ) where kings as players discuss diplomacy in first person over voice. Or join war. Bragging about their army, trading units in game in a FFA ( Transferring owner ship of a unit group over to your ally is never seen in AoE idk why )
Would be amazing if I could experience being in a ship battle and see my ship being fired upon by projectiles and see the ship sink (same for my opponent )
AoE4 could also have different viewing angles for different units. So an elephant has a higher line of sight for war in Wars , while an infantry unit has a lower line of sight. Hills blocking the way of what army the opponent is having.
You could be a scout too . So Co OP would be so fun. Your mate builds his base in 3rd person view and you scout looking for army and so on.
The game could take a minecraft cum AoE 2 DE theme . Where once the base is built , you can just walk around as king. There could be a king snipe mod where you could send hitmans to kill human players ( kings ) and avoid snipes from AI or 8 other humans in a giant castle with many walls .
First Person opens 100’s of new categories in Age Of Empires , maybe a good source of revenue for Microsoft selling these DLC’s as a supplement tto the main game ( Like Unity does )