There's two types of multiplayer, hotseat and PBEM. I do know there's some hotseat players around somewhere on Gameranger or something, but it's Play By Email I'm advertising here.
In Play By Email, combat between players is autoresolved, walls are almost irrelevant in large city-battles, and concealment is far stronger than in live games because you don't get a chance to see a Concealment-capable unit moving between patches of forest as long as they start and end their turn concealed. Heroes in AoW1 are also rather hideously overpowered if you max out their DEF on levelup, and lizardmen, archers, and elephants are vastly superior to most basic tier troops. Despite all this, there's still plenty of strategic play to be had especially in regards to scouting and maneuvre, and the imbalance isn't the sort that biases things much in favour of a particular player or race, against the others. AoW2 is more balanced but I've been having a great time with PBEMs in both.
Games consist of each player playing their turn, which is then automatically emailed to the next guy, and automatically extracted into their Email In savegame folder (and makes a pinging notification noise when you get your turn). This is thanks to the Email Wrapper
http://aow.heavengames.com/downloads/showfile.php?fileid=1122.
A typical match lasts weeks or even months, depending on the number of players and how prompt they are playing their turns. We like to post in a Turnlog to keep track of whose turn it is, here's an example
https://af.gog.com/forum/age_of_won...rwocky_catermune_southern/page1?as=1649904300
This is of course vastly more convenient than hotseat - some of us have jobs, kids, etc - but not to everyone's taste.
There can be some minor issues getting the games or wrapper to work with windows 10 / gmail etc, but I can point to fixes.