Question about alliance battles

[TheGreenOne]

Can someone explain me why this happens http://prntscr.com/cpa2qi ?

the armies are equal 1m archers 1m speras and 1m paladins.

Should not the defender win? it has better upgrades and the terrain is mountain with forests.

And simulator does not say ¨some wins attacker and some times win defender¨, i simulated like 20 times and every time attacker wins.