I personally would want a pretty generic but extensive unit roster but with slightly more unique units (3-4) per civ and maybe more differences between the generic unit lines if they have to feel more different to each other.
I personally am pretty happy with how the units are handled in AOE2, so in my opinion they shouldn’t feel too different.
Prepare to be quoted, Andy! 
I enjoyed AoM but I can’t say the same about AoE3/AoEO.
Anyway as I said before it’s not possible to be fully unique because most civz got the same kind of units - the differences are minimal.
To be very clear, I 100 percent agree that AoE4 should not include fully asymmetric civs, and I apologize if I did not make that clear. I tried to specifically cite three other Age of Empires games as examples of the kinds of asymmetry I am suggesting we see in AoE4.
All of those games include a basic set of Buildings that all civs draw from and that most civs have without any modification but that are modified in some civs in intelligent ways that improve gameplay and harken back to history. The civs also often contain some buildings that only certain civs share and also some civ-specific buildings.
Similarly, the civs in these games contain a number of Units that are fairly universal (such as villagers, market caravans, fishing boats, spearmen) and another set of units that appear in some, but not all civs (such as archers, slingers, melee cavalry, some siege weapons), and a third set of units that are unique to each civ.
I am being very general here and we could certainly be more specific. But I think the idea is pretty noncontroversial: after AoE2, Ensemble Studios and Age of Empires moved in a direction of fewer, more diverse civs. It makes for much more compelling gameplay and exploration.
Certainly AoE2 still has plenty of lessons in other areas of game design to teach us, but we should not blindly copy it.
One of the joys of us who prefer the games after AoE2 is knowing how easily it is for people to misunderstand our opinions and attack things we aren’t saying. I am not trying to disown AoE2. AoE2 is great. But we need a game that draws from the entire corpus of AoE.
I think the sales numbers disagree with you quite a lot…
Just so I am sure I understand your understanding of the facts, are you suggesting that Age of Mythology and Age of Empires 3 were both commercial failures?
To me this is the worst of the series. The only good thing for that time was the new graphic except that AoE1-2-M were far better.
I do not deny it, I would be curious to know how much the various titles have sold.
I do not prefer AoE3, either. But that does not mean I believe it does not contain lots of lessons and improvements that are important for AoE4 to use. Every video game is a bundle of features and ideas. Just because I overall prefer the bundles in other titles does not mean that I think we should completely ignore the other games and completely clone my favorite version.
All too often, this community seems to face some bizarre and unhelpful slippery slope arguments when someone suggests anything. Players for whose favorite Age game does not contain that feature fly off the handle and argue that any idea from any other game than theirs is valueless.
This is seen worst where players in favor of AoE2 prop up its sales numbers and playerbase as the authority that we should adopt every single feature in AoE2. It’s blind loyalty and not how good games are designed.
AoE2 obviously does lot of things right, but as a community, we should be intelligent enough to be able to hold that concept in our heads at the same time as the concept that other Age games may have done other things better.
One good example of this is how Ensemble replaced the reseedable Farms of AoE1 and AoE2 with infinite farms in AoM, AoE3, and AoEO. This feature was roundly lauded and now the new updated AoE1DE and AoE2DE include mechanics similar.
Another example are Walls. In AoE2, you had wooden palisade walls in Age 2 and then had to remake brand new stone walls all over again in Age 3. Again, Ensemble replaced this AoE2 feature in AoM, AoE3, and AoEO with Age 1 wooden walls that simply upgrade up to stone walls starting in Age 2. There are dozens more examples.
What do you think is unique of AoE3 and that would be good?
It’s something I dislike but okey.
Does not make much sense but okey.
Sorry, I edited it above to cut you off. For starters, Farms and Walls. Also civ design.
The only good thing was the fact melee units could use torches to destroy buildings. But for example the gameplay was not the same as was in AoE1-2-M, the card system was a fail. Dunno I had a bad experience and I’m one of those who bought the collectors edition XD
Yeah that’s something related to graphic like the melee using torches.
Nobody here is asking for a card system like AoE3. Similarly, I dont see any AoM fans demanding AoE4 contain Myth Units or AoEO fans demanding AoE4 contain its graphics style or business model. There’s a lot more to the other Age games than these features.
Well that was not bad and we get it. They said we have hero units for each faction with specific powers. That was just my opinion (over all) about my experience in the game - the gameplay is what counts 
Haha! I would like myth units, but I am not seriously asking for them.
The eagle of the trailer is one of the powers of the Khan of Mongols - dunno how op those units will be. Anyway I have never said to not pick the graphic feature from AoE3 considering that was a good thing 
For me，a 20 years AOE2 player，the card system is most interesting part in AOE3.It make PVP game extreme strategic, and give each civ hundreds of tactics.But the main city level design is a bad idea. It make PVP game unfair and ruin the talented card system.
I personally liked the Equip cards of of Age Online because you sincerely could say that is “your” civilization and yours only
The most basic i hope more then the look of buildings and unique units we at least had units by “region/continent” i always though it is very stupid the Japanese having the Champion and the samurai(both are basically the same in the idea i know that they have different stats but on Japan it was either a peasant with a katana or Samurai…) in brief civilizations a lot less generic mainly the tech trees that on 2 all civilizations had like 5 tech different from each other at most so i hope that at least each civilization by continent/region west Europe, east Europe, Asia, Middle East, America to be completely different on troops and Techs
Yes, the card system added more complexity and strategic possibilities into the game. Although I understand that someone who was already used in playing AoE, AoE2 and Myth for some years, those cards were a huge headache. It really made the gameplay more complex and required more study per civ to master it. That was however compensated by removing Stone as a resource and replacing it with Experience. But people do not adapt to new things easily. Most folks had already picked their god game when these things were introduced and its all a matter of preference in the end.
The home city levels were indeed a bad idea and the civ’s card decks often quite unbalanced. Maybe all those things combined were what made the card system so notorious.
Aoe3 introduced many new things and improvements. Another one that I particularly liked were the neutral native settlements. The players are able to ally them and use their armies and various bonuses that they offer against their enemies. It would be really interesting to see something similar featured in AoE4.