I don't know if it is the game's fault, or if it is only a rare thing, which occurs near never.
But I've noticed it 2 times :
When there is a War Elephant on a tile with other units. (AI)
If the Elephant is first shown at the top because he is the most powerful,
If another unit of the group attacks, instead of being the only unit which you see on the tile because he is the "fighter" of the tile, we see, him, but we see the War Elephant too in the same tile, so we see both units at the same moment ! We see the attacker, and the War Elephant, in the same time.
This is the same when a Catapult that is on the same tile of an Elephant that is on the top normally, when the Catapult bombards a city, we see the Catapult AND the Elephant on the tile when the catapult attacks, and we see both at the same time.
So instead of seeing only one unit, we see 2 that are mixed, only because it was the Elephant that was shown before the other unit's attack.
But I've noticed it 2 times :
When there is a War Elephant on a tile with other units. (AI)
If the Elephant is first shown at the top because he is the most powerful,
If another unit of the group attacks, instead of being the only unit which you see on the tile because he is the "fighter" of the tile, we see, him, but we see the War Elephant too in the same tile, so we see both units at the same moment ! We see the attacker, and the War Elephant, in the same time.
This is the same when a Catapult that is on the same tile of an Elephant that is on the top normally, when the Catapult bombards a city, we see the Catapult AND the Elephant on the tile when the catapult attacks, and we see both at the same time.
So instead of seeing only one unit, we see 2 that are mixed, only because it was the Elephant that was shown before the other unit's attack.