A very long time and I’m aware of all of the points you’ve made. Let’s talk about them:
2) Orcs have burrows yes, but they have to walk to them and they die in 2 seconds to anything. (They’re also not mining gold while they’re burrowed)
3) The ones in the gold mine are protected, yes, but the ones that aren’t are by a wide margin the easiest to kill and NE has more stuff that requires lumber.
4) Humans can turn militia, yes, but even though they gain armor they still are easy to kill and when they’re militia, they can’t mine gold. Every time a Human player calls militia, that’s a loss (really delay but it’s technically a loss if you don’t mine out- an advantage either way). You don’t even have to kill any peasants (or peons) to do damage to the Human player if you can provoke them to militia. For these reasons I find the advantages you frame them as having to be wildly overstated. Additionally, millitia can only be called in your main base unless you upgrade your expo to keep, due to an ages old change (And if you have to rebuild your main town hall, it won’t call militia anymore either unless you upgrade to keep)
Also while UD don’t have a special building or a way to power up the acolytes, your basic food building is also a tower and in my experience you thus naturally find more towers in a UD base compared to the other races just from the convenience of simply upgrading something you have to build anyway.