[Executor]

"if your neighbor sees you playing Kailasa, what's stopping him from rounding up a group of indie archers and breaking down your door?"

Time is, can you really buy enough indie archers to counter Kailasa so early? You would need a great deal of archers to do so.
When you get to the point where you have several forts with cheap acrhers Kailasa is going to have some magic and other troops to support the yavanas.

What you're saying is impossible. What's to stop me from rounding up a group of indie infantry to stop those archers? Or buying my own archers put to fire archers? Indie archers won't get you anywhere against Kailasa.

If you're playing Sauromatia, sure they'll be a pain in the *** since nations like that are going to use archers anyway but even then there are ways to avoid archers.

An army of yavanas against an army of archers as the same gold cost, yavanas are gonna cut them to shreds, and they are a part of your general strategy unlike archers who you're gonna use in only certain situations but will still cost you twice as much to keep since yavanas are sacred.

And with Kailasa you don't need big armies running around. Several small armies are much more effective and will make it harder for a big group of archers to stop.