Summoning an Iron Golem riding a Zombie makes the Zombie blind

The Zombie is a NoAI zombie.
I think this is the correct command.
(Actually I did not test it so I can be wrong)

/summon VillagerGolem ~ ~1 ~ {PlayerCreated:0,NoAI:0,Silent:1,Riding:{id:"Zombie",Equipment:[{},{},{},{},{id:wool,Damage:4,Count:1}]

The Golem is a NoAI but the zombie definitively moves but it doesn't attack players or anything.
BTW, summoning a ghast riding a giant is the same thing, the ghast don't fire at the player.

It's like both mobs block the view of the other.

I think that this may be caused by the zombie being hostile to the Golem (though I have yet to test it).
About the Ghast issue, that may be MC-49640.

Not sure if there's a link with the zombie being hostile toward the Golem because replacing it by a Villager makes the zombie focus working well. For example 2 villagers riding 2 zombies will make both zombies trying to kill the other's villager. But with golem, it just doesn't work at all.

Confirmed for both Golems and villagers, however it only seems to happen half of the time.

Is this still an issue in the current Minecraft Snapshot 15w47c or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Cannot confirm for 16w06a
The updated command is

/summon Zombie ~ ~1 ~ {ArmorItems:[{},{},{},{id:"wool"}],Passengers:[{id:"VillagerGolem",NoAI:1b,PlayerCreated:0b,Silent:1b}]}

While the Zombie acts a little bit strange by only attacking and damaging the VillagerGolem sometimes, it still chases the player