Protection against mold formation in glass wool/core insulation

Good day,
one always hears that the glass wool/ core insulation must under no circumstances get wet; because of mold and also because of the then missing insulating effect.
Now my foreman said it would be enough to cover the glass wool and clinker with a foil. See photo.
My question to the experts... is that really enough??? The roof is not on yet, unfortunately. Because it would be in the way during the clinker work on top... /
Because, honestly, the water that rains against the wall (and right now it’s really pouring frequently!) runs 1000% down the wall and past the foil; into the glass wool.
My foreman says he has been doing that for 40 years. Besides, it would dry again.

???
What do you think?
Thanks in advance!
Best regards

No one has an opinion about that ???

Basically, you are right that the material loses most of its insulating ability when it becomes damp to a certain extent. However, there is supposed to be insulation wool by now, at least some manufacturers advertise it this way, that almost regains 100% of its insulating ability after drying. I don't know if that can be believed. Someone who knows about this would really have to speak up. But the technicians are few and far between here...

Hello frogger. What do you think of the following option: build up the bricks, and then have a specialist company insulate it afterwards with insulating foam. You won’t see anything of it afterwards, I did it that way.