Reimian Empire

I suspect that this wave will destroy our Persian units.

Why? The wave affects units in a line, moving away from the caster. We'll just stand behind it, and everything will be fine. If you're worried that the entire palace will collapse, then you just need to identify a wall that isn't load-bearing, and that's it. It's clear that if there's an arch or column that clearly supports the ceiling, then you shouldn't shake it up. But otherwise... Well, in the worst case, the room behind the door will be destroyed. But it's not a big deal; we have two more just like it.